Motorola Astro Xts5000 Detailed 6881094c31 E Manual

							November 16, 20066881094C31-E
3-32Theory of Operation: VOCON Board
The USB transmitter is enabled when the RS232_USB* and USB_TXENAB signals are both driven 
low by the dual-core processor. The single-ended data is output from the dual-core processor on the 
UTXD1_USB_VPO pin and goes to USB1_DAT_TXD on U501. The data is driven out differentially 
on the USB1_DP and USB1_DM pins, which go to the side connector. The dual-core processor 
sends the single-ended zero signal from pin USB_VMO to the USB1_SE0 pin on U501.
When a USB cable is attached, pin CTS_CABLE_DET_5V is driven low and goes through level 
translation in U501 and the output of CABLE_DET_3V is pulsed low and sent to the dual-core 
processor. This line controls the USB and RS232 modes so that the data that is on those lines are 
routed to the USB transceiver when a cable is detected. If a USB cable is not detected, 
CABLE_DET_3V is high, the transceiver is put in suspend mode and the DP and DM pins can now 
handle 5V tolerance for RS232 mode.
3.2.4.2.3  One-Wire Support
New options and accessories that attach to the side connector are identified by the dual-core 
processor using the One-Wire protocol. The One-Wire pin on the side connector serves as the One- 
Wire data pin. This signal is connected to the ONE_WIRE_OPT pin. This pin is connected to the 
dual-core processor One-wire bus ONE_WIRE_UP through the Mako IC, U501, internal isolation 
switch controlled by the SPI commands sent from the dual-core processor. This isolation is needed 
to prevent possible contention on the One-Wire bus when a smart battery is attached to the radio.
These new accessories are to ground, designator R245, of the side connector. When this occurs, the 
digital-support IC pin KVL_USB_DET_X is asserted and the dual-core processor detects the 
change. The dual-core processor then sends a command through the SPI lines to the U501 Mako IC 
to connect the side connector One-Wire line to the dual-core processor One-Wire bus. In the case of 
the USB cable, the dual-core processor reads the One-Wire data from the cable and, upon 
determining that a USB cable is attached, programs the digital-support IC for USB mode.
3.2.4.2.4  Watchdog Timer
In kit NNTN5567A, the watchdog timer is a 125ms counter that is integrated into the MAKO IC U501 
and used during the power down sequence. The MAKO IC will begin the power down sequence 
when a low-to-high transition occurs on MECH_SW pin (MAKO pin E4). Once this transition occurs, 
the MAKO IC begins the watchdog timer. Upon expiration, RESETX (MAKO pin C5) is asserted and 
all of the MAKO regulators are shutdown. The dual-core processor can refresh the watchdog timer 
so that the software has enough time to complete its tasks before the power is taken away.
3.2.4.2.5  32 kHz Oscillator and CMOS Output
There is an internal 32kHz oscillator circuitry to the MAKO IC U501 that is based off of a 32.768 kHz 
crystal Y501 and additional load capacitors C501 and C502. The output of the 32 kHz oscillator is a 
logic_vdd voltage (approximately 2.9 volts peak-to-peak), 32kHz +/- 20% square wave on pin 
GATED_32K_CLK. This 32 kHz signal is routed through an analog switch U512 and sent to the dual-
core processor CKIL pin. This signal is only used to boot up the dual-core processor.
After the dual-core processor boots up, the select input (R599) of the analog switch is asserted high 
allowing for the processor to receive an accurate 32.768 kHz, 2.9 V peak-to-peak square wave. This 
signal is generated by tapping the output of the 32.768 crystal and buffering the signal with the 
following components: U513, R545, R546, C543, C592, R542, and R541. The 32.768 kHz clock 
signal allows for the completion of real-time applications.
3.2.4.3  ESD Protection Circuitry
See Figure 8-63, “NTN9564B VOCON Universal Connector Circuit,” on page 8-97 for schematic 
details of the following discussion. 
						

							6881094C31-ENovember 16, 2006
Theory of Operation: VOCON Board3-33
Several components on the VOCON board protect the circuitry from ESD. The side connector signal 
lines have ESD protection components on them since they are exposed. These protection 
components include:
• 5.6-V zeners VR205, VR206, VR220, and VR221 on the SB9600 lines, RS232 lines, 
microphone lines, and option-select lines
• 12-V zeners VR201, VR203, and VR209 on the internal and external speaker audio lines
• 13-V zener VR204 on the OPTB+ line
• Low-capacitance ESD suppressors D203, D204, D205, and D206 on audio lines, USB data 
lines, and option-select lines
There were also several protection diodes on lines connected to the Flipper IC. These include D302, 
D303, D304, D305, D306, D307, and D308. ESD protection for the battery status line is provided by 
a 5.6-V zener VR501. 
						

							November 16, 20066881094C31-E
3-34Theory of Operation: VOCON Board
3.2.4.4  Universal Connector Interface Circuitry
See Figure 8-63, “NTN9564B VOCON Universal Connector Circuit,” on page 8-97 for schematic 
details of the following discussion.
Some important components on the universal connector interface are two op-amps. The first op-
amp, U201, is used as a comparator for the option-select 1 line. The comparator threshold is 
determined by the voltage-divider network of R257 and R258. Similarly, the other op-amp, U202, is 
used as a comparator for the option-select 2 line. The comparator threshold is determined by the 
voltage-divider network of R240 and R243. The remaining components consist of current-limiting 
serial resistors and noise-suppressing shunt capacitors.
3.2.4.4.1  Universal Connector and Option Selects
The universal connector is located on the side of the radio. It is the external port or interface to the 
outside and is used for programming and interfacing to external accessories. The universal 
connector connects to the VOCON board at connector J101 via a flex circuit that is routed inside the 
external housing. Connections to the universal connector and J101 on the VOCON board are shown 
in Figure 3-10 on page 3-34 and Figure 3-11 on page 3-34.
Figure 3-10.  Universal (Side) Connector
Figure 3-11.  VOCON Board Connector—J101
OPT_SEL1
EXT_MIC
OPT_SEL2
RTS
SB9600_BUSY
RS232_DOUT/USB_D+EXT_SPKR
12
131
2
OPTB+/VPP
SPKR_COM
GND
CTS
RS232_DIN/USB_D-
SB9600_DATA/KEYFAIL
MAEPF-27415-O
1 3 537 35 39
36
38 40
2 4
6
J101
OPT_SEL1
EXT_SPKR
EXT_MIC
OPTB+/VPP
OPT_SEL2
SPKR_COM
RTS
GND
SB9600_BUSY
CTS
RS232_DOUT/USB_D+
SB9600_DATA/KEYFAIL
RS232_DIN/USB_D- 11
9
13
12
7
5
10
3
8
1
6
2
4
Signal Name                   J101-Pin #
MAEPF-27452-O
---------------------------------------------------------------------- 
						

							6881094C31-ENovember 16, 2006
Theory of Operation: VOCON Board3-35
Most of the signals are extensions of circuits described in other areas of this manual. However, there 
are two option select pins (see Table 3-5) used to configure special modes: Option Select 1 and 
Option Select 2. These pins are controlled by accessories connected to the universal connector. 
Table 3-5 outlines their functions as defined at the universal connector. In the case of the XTS 
Vehicular Adapter (XTVA), Option Select 1 pin is connected to Option Select 2 pin by a diode internal 
to the XTVA.
3.2.4.5  Display Module
An optional, integral, 96 pixels by 64 pixels, bit-mapped, liquid-crystal display (LCD) module is 
available with either a 3 x 2 keypad with a navigational button (Model II radios) or 3 x 6 keypad with a 
navigational button (Model III radios). The display module is connected to the VOCON board through 
flex connector J301. The display module uses chip-on-film technology and is not field repairable.
3.2.4.5.1  7285726C01 Display Module
NOTE:The NTN9564 VOCON kit is only compatible with the 7285726C01 display module.
The 7285726C01 display module is controlled by the Patriot IC MCU core, which programs the 
display through the EIM data lines D0 - D7 (pins 9 through 16, respectively), the display chip select 
line (pin 5), the EIM read/write line (pin 8), and the EIM address 0 line (pin 7) that is used to select 
the register to be programmed. The Patriot IC can reset the display module through pin 6. The 
display is supplied with 1.8 V (B102) to pin 17 and 3.0 V (B101) to pin 18. Display backlighting is 
controlled by the Patriot IC GPIO line BL_EN signal through components R140 and Q101. The LEDs 
on the display module are powered by 5 V going through resistors R101, R102, R103, and R104.
3.2.4.5.2  7285726C02 and 7285726C03 Display Modules
NOTE:The NNTN4563 VOCON kit is compatible only with the 7285726C02 display module, while 
the NNTN4819 VOCON kit is compatible only with the 7285726C03 display module. Check 
the model charts for display part number compatibility with the NNTN4717 VOCON board.
The 7285726C02 and 7285726C03 display modules are controlled by the Patriot IC SPI bus, which 
programs the display through the serial data line (pin 16), the serial clock line (pin 15), chip select 
line (pin 5), and register select line (pin 7) that is used to select the register to be programmed. The 
Patriot IC can reset the display module through pin 6. The display is supplied with GCAP II V2 
regulated voltage (B101) to pins 17 and 18 or 2.9V MAKO IC regulated voltage (NNTN5567 VOCON 
kit) to pins 11 and 14. Display backlighting is controlled by the Patriot IC GPIO line BL_EN signal 
through components R140 and Q101. The LEDs on the display module are powered by 5 V going 
through resistors R103 and R104.Table 3-5.  Option-Select Functions
FunctionOption 
Select 1Option 
Select 2
External PTT00
No Function (Normal)11
Man Down10
External Speaker01
XTVADiode cathode Diode anode 
						

							November 16, 20066881094C31-E
3-36Theory of Operation: VOCON Board
3.2.4.6  Keypad Module
The keypad module is either a 6- x 3-button (Model III) or a 2- x 3-button (Model II) module with 
backlighting.
The keypad module is connected to the VOCON board through flex connector J107. The keypad is 
read though a row-and-column matrix made up of ROW1, ROW2, ROW3, ROW4, ROW5, ROW6, 
and COL1, COL2, and COL3. When a key is pressed, a row and a column are connected to each 
another. The Patriot IC determines a key press by a scanning algorithm. Each column line is 
configured as an open drain output and pulled low. The Patriot IC then scans the row pins (each row 
pin has an internal pull-up resistor). If a row signal is read low, then the Patriot IC determines that a 
key was pressed. If none of the row signal lines are low, then another column line is pulled low and 
the row scanning routine occurs.
The keypad backlighting is controlled by the Patriot IC GPIO BL_EN, and that signal goes to pin 6 of 
the J107 connector. Pins 7 and 8 are supplied with 5 volts, which is used to power the LEDs on the 
keypad module.
3.2.4.7  Controls and Control Top Flex
The universal flex assembly contains an On/Off switch/volume control knob, frequency selector 
switch, push-to-talk (PTT) switch, monitor button, several function-selectable switches, universal 
connector, speaker, and microphone.
The housing assembly top controls include the On/Off switch/volume control (S1), a 16-position 
mode-select switch with programmable two-position concentric switch (U1), a programmable three-
position (A,B,C) toggle switch (S2), and a programmable top (orange) button (SW3). The side 
controls include three programmable, momentary, pushbutton switches (side button 1 [SB2], side 
button 2 [SB3], top side button [SB1]) and a PTT switch (SW2). These components are connected 
through a flex circuit to the controller at J101 (see Table 3-12, “Control Top Flex,” on page 3-37). The 
assembly also contains the radios internal speaker and internal microphone.
UNSW_B+ is routed through switch S1 to provide the B+SENSE signal, which is used to activate the 
SW_B+ and GCAP_B+ voltages that, in turn, power up the radio. Volume control is also provided by 
S1, which contains a potentiometer biased between V2 regulated voltage and ground. The VOL 
signal is a voltage level between V2 regulated voltage and ground, depending on the position of the 
rotary knob. The VOL signal is fed to buffer U507 pin 3, and then the output of the buffer is voltage-
divided down to 2.5 volts before the signal goes to the GCAP II IC AD5 pin. The Patriot IC reads the 
GCAP II IC A/D value through the SPI bus, and from this reading, the Patriot IC DSP adjusts the 
speaker volume. In NNTN5567 VOCON kit, the VOL signal is fed directly to the MAKO IC U501 AD1 
pin. There is no buffer or voltage division since the MAKO ICs AD pin is high impedance and tolerant 
to 3 V. The dual-core processor reads the MAKO IC A/D value through the SPI bus, and from this 
reading, the dual-core processor DSP adjusts the speaker volume.
Switch S2 is the three-position, programmable, toggle switch typically used for expanded
zone/channel selection. The switch can output the following voltages: 0 volts, half of the V2 regulated 
voltage, or V2 regulated voltage (measurable at R231). The switch is connected to the GCAP II IC 
AD1 input pin through the voltage divider network of R519 and R523. But for NNTN5567, the switch 
is connected to MAKO IC AD3 input pin through R224. The Patriot IC reads the A/D value through 
the SPI bus, and it uses that reading to determine the position of the toggle switch.
The programmable top (orange) button SW3 is typically used for emergency. This button, along with 
programmable side buttons SB1 through SB3, is connected to a resistor divider network, biased 
between V2 regulated voltage and ground. This network, made up of R1, R2, and R3, provides a 
voltage level, controlled by whichever button is pressed, to pin 3 of buffer U504. The output of the 
buffer is voltage- divided down to 2.5 volts before the signal goes to the GCAP II IC AD0 pin. The 
Patriot IC reads the GCAP II IC A/D value through the SPI bus, and it uses that data to determine 
which button was pressed. 
						

							6881094C31-ENovember 16, 2006
Theory of Operation: VOCON Board3-37
LED D1 is the TX/RX indicator. LEDs D2 through D6 are used for backlighting the frequency knob.
U1 is a binary-coded switch. The output pins from U1, which are connected to GPIO pins on the 
Patriot IC, provide a four-bit binary word (signals RTA0, RTA1, RTA2, and RTA3) to the MCU, 
indicating to which of the 16 positions the rotary is set. This switch provides an additional output, 
TG2, which is typically used for coded or clear mode selection. It is an input to the Patriot IC 
TOUT8_PD4 GPIO pin. Selecting clear mode pulls this signal to a logic low, and it can be monitored 
from R234.
Figure 3-12.  Control Top Flex
3.2.4.8  System Clocks
The Patriot IC is supplied with two clocks. The first clock, a 16.8 MHz sine wave, comes from the RF 
interface connector P201 pin 7. It is conditioned by the clock buffer circuit, which includes Q450, 
Q451, L450, C450, C452, C452, R450, R451, R452, R453, R454, and R455. The output of this 
buffer (C452) goes to the Patriot IC CKIH pin as well as the Flipper IC REF_16_IN (C307).
R1
91K
R3
150KSB1
(MON)
SB2S2
TOGGL
ESWITCH
SB3
SW3
TOP BUTTON
SW2
PTT1
22 4
3
1 D1 V2
4
8
BU1
Zone/Channel
Select
CC
A
R901 S1
VOL S901
ON/OFF
1
2 3
4 5
UNSW_B+ (33)
V2 (35)
TOGGLE SWITCH (TG1)
 (34)
VOL (31)
EMERG (14)
B+_SENSE (32)
GREEN_LED (22)
RED_LED (21)
INT_PTT* (38)
RTA0 (27)
RTA1 (24)
RTA2 (26)
RTA3 (25)
SECURE/CLEAR (TG2)
SWITCH (23)
DGND (15)
MONITOR (17)
BL_EN (20)
INT_SPKR (40)
SPKR_COM (37)
INT_MIC (36)
AGND (39)
1
2 To Controller
J101
R2
68K
MAEPF-27416-A
2 4
3
1 D2
2
24
3
1
1
LS1
MIC
2 C11D4
2 4
3
13
1
3
1 D5
2 4D3
2 4D6
 V2
V2
 V2 
						

							November 16, 20066881094C31-E
3-38Theory of Operation: VOCON Board
The other clock supplied to the Patriot IC is a 32.768 kHz square wave. This clock is generated by 
the Flipper IC internal oscillator and an external 32.768 kHz crystal Y301 and is connected to the 
Patriot IC CKIL pin.
3.2.5 VOCON Audio Paths
This section describes the VOCON transmit and receive audio paths. See Figure 8-67, “NTN9564B 
VOCON Audio and DC Circuits,” on page 8-101 for schematic details of the following discussion.
3.2.5.1  Transmit Audio Path
Refer to Figure 3-13. The internal microphone audio enters the VOCON board through the universal 
connector J101 pin 36, and the internal microphone bias is set by circuitry that includes R531, R533, 
C519 and C521. The internal microphone signal is connected to the MICIN_NEG pin, which is the 
input terminal on the GCAP II IC internal op-amp A3. The gain of the A3 op-amp is set by the values 
of R540, R555, and the resistance of EEPOT U509 (digital potentiometer), which is programmed by 
Patriot IC GPIO lines.
The external microphone audio enters the VOCON board through the universal connector J101 pin 
13, and the external microphone bias is set by circuitry that includes R563, R565, C547, and C548. 
The external microphone signal is connected to the AUX_MIC_NEG pin, which is an input terminal 
on the GCAP II IC internal op-amp A5. The gain of the A5 op-amp is set by the values of R566, 
R561, and the resistance of the EEPOT U509.
The Patriot IC, through the SPI bus, programs a multiplexer to select one of the microphone signals. 
Then, the selected amplified microphone signal goes through a programmable gain amplifier before 
it goes to the CODEC for A/D conversion. The resulting digital data is filtered and sent to the DSP on 
the SAP CODEC_TX line from the GCAP II IC TX pin. After additional filtering and processing, the 
DSP sends the data-out from the STDB pin to the RF interface connector P201 pin 4 (TX_DATA), 
which is connected to the DAC U203 on the transceiver board.
Figure 3-13.  VOCON Transmit Audio Path
TP214INTERNAL MIC
Bias (R531,
R533, C519, C521)
and Input
(R540, C522)
EXTERNAL MIC
Bias (R563,
R565, C547, C548)
and Input
(R566, C549)
GCAP II IC U501
EEPOT U509
0 - 50K, 256 taps
MIC PREAMP
A3
Gain =
-14dB to 16dB
MIC PREAMP
A5
Gain =
-14dB to 16dB
EEPOT U509
0 - 50K, 256 tapsMUXPGA
-7 to +8dB
in 1dB steps
Set at 6dBCODEC A/D
13-bitHP FILTER
cutoff = 200HZ
LP FILTER
cutoff = 3.5KHZ
Patriot GPIO
PB4, PB5,
PB6, PB7Patriot SPIBPatriot SAP/BBPFlipper
U301
RF D/A
U203
(On RF Board)
TX_SSI_FSYNC
TX_SSI_CLK
TX_DATACODEC_FSYNC
CODEC_DCLK CODEC_TX GCAP_CE, SCKB
SPI_MISOB
SPI_MOSIB AUX_OUT
R561
MIC_OUT
R555
4
EEPOT_CS_EXT*
EEPOT_CS*
EEPOT_U_D*
EEPOT_INC*
4
3
MICIN
_NEG
AUX_MIC
_NEG
MAEPF-27418-A 
						

							6881094C31-ENovember 16, 2006
Theory of Operation: VOCON Board3-39
3.2.5.2  Transmit Audio Path (for kit NNTN5567A)
Refer to Figure 3-14. The single-ended internal microphone audio enters the VOCON board through 
pin 8 of the M102 contact, and the internal microphone bias is set by circuitry that includes C550, 
R550 and R552. The internal microphone signal is connected to the INT_MIC_P pin, which is the 
input terminal on the Mako IC internal op-amp G1 after the signal is multiplexed. The gain of the G1 
pre-amp is set to +15 dB, which is programmed by dual-core processor SPI lines.
The external microphone audio enters the VOCON board through the remote connector J102, pin13, 
and the external microphone bias is set by circuitry that includes C551, R551 and R553. The 
external microphone signal is connected to the EXT_MIC_P pin, which is an input terminal on the 
Mako IC internal op-amp G1 after the signal is multiplexed. The gain of the G1 pre-amp is set to +15 
dB, which is programmed by dual-core processor SPI lines.
The dual-core processor, through the SPI bus, programs a multiplexer internal to the Mako IC to 
select one of the microphone signals. Then, the selected microphone signal goes through the G1 
pre-amplifier stage and on to a programmable gain amplifier (G2) before it goes to the CODEC for A/
D conversion. The resulting digital data is filtered and sent to the DSP on the CODEC_TX line from 
the Mako IC VC_TX3V pin. After additional filtering and processing, the DSP sends the data-out from 
the STDB pin, labeled TX_SSI_DATA to the RF interface connector P201 pin 4 (TX_DATA), which is 
connected to the DAC U203 on the transceiver board.
Figure 3-14.  VOCON Transmit Audio Path
Internal Mic Bias
(C550, R550, R552)
and InputINT_MIC_P
Internal Mic Bias
(C551, R551, R553)
and InputEXT_MIC_PMUXPre-amp
G1 Gain
= 15 dB
MAKO_CS
SPI_MISOB
SPI_MOSIB
SCKB4
Patriot
SPIBPatriot
SAP/ BBPMAKO IC U501
Amp G2
Gain = -30
to 0 dBCODEC
A/D 16-
Bit
CODEC_TX
CODEC_FSYNC
CODEC_DCLK
TX_SSI_FSYNC
TX_SSI_CLK
TX_DATA3HPF = 200 Hz
& LPF = 3.4
kHz cutoff
RF D/A
U203
(On RF Board) 
						

							November 16, 20066881094C31-E
3-40Theory of Operation: VOCON Board
3.2.5.3  Receive Audio Path
Refer to Figure 3-15. The receive audio data comes from the Abacus III IC U500 through the RF 
interface connector P201 pin 12 (RX_DATA) to the Patriot IC SRDB pin. The DSP decodes the data 
and sends it out through the CODEC_RX line to the GCAP II IC RX pin. The CODEC filters and 
converts the digital data into an analog audio signal, which, in turn, is sent to a programmable gain 
amplifier. The Patriot IC programs a multiplexer to route the audio signal to the A4 amplifier, which 
has a fixed gain of 3.5 dB. The output of the A4 amplifier is pin EXTOUT.
From the EXTOUT pin, the audio signal goes through the pre-amplifier U502 and then to the audio 
power amplifier U503, which together provide approximately 30 dB of gain. The Patriot IC selects 
whether the amplified audio is routed to the internal speaker or the external speaker.
Figure 3-15.  VOCON Receive Audio Path
3.2.5.4  Receive Audio Path (for NNTN5567A)
Refer to Figure 3-13a. The receive audio data comes from the Abacus III IC U500 through the RF 
interface connector P201 pin 12 (RX_DATA) to the Patriot IC SRDB pin. The DSP decodes the data 
and sends it out through the CODEC_RX line to the Mako IC VC_RX3V pin. The CODEC filters, 
adds digital programmable gain G1, then converts the digital data into an analog audio signal, which 
in turn is sent to programmable attenuator G3. The signal is then sent through an internal 
programmable differential preamplifier (G4) to add gain and outputs the signal on pins VC_OUT_P 
and VC_OUT_M of the Mako IC.
This output from the preamp is then filtered through circuitry R597, R598, C590, C565, C564, and 
then sent back to 2 independent internal BTL differential power amplifiers, G5 & G6, of the Mako IC. 
The power amplifiers are programmed to a fixed gain of 26 dB through the dual-core processor SPI 
lines and PA control registers.
GCAP II IC U501
LP FILTER
cutoff = 3.5KHZHP FILTER
cutoff = 200HZGCAP CODEC
13-bit D/APGA
-35 to 0dB
in 5dB steps
Default 0dBGCAP A4
Gain = 1.5
(3.5dB)
Audio_PA_Enable
0
0
1
1Audio_Mode_Sel
0
1
0
1Audio PA Status
Audio Off
Mute
Audio On
Audio OnMode (V)
1.5V 
						

							6881094C31-ENovember 16, 2006
Theory of Operation: VOCON Board3-41
The dual-core processor selects whether the amplified audio is routed to the internal speaker or the 
external speaker through the SPI lines based upon which amplifier is turned on as shown in the PA 
control block. The output audio is routed on Mako IC pins INT_SPKR_P and INT_SPKR_M for 
internal and EXT_SPKR_P and EXT_SPKR_M for external speaker lines.
Figure 3-16.  VOCON Receive Audio Path (for kit NNTN5567)
3.2.6 Radio Power-Up/Power-Down Sequence
The radio power-up sequence begins when the user closes the radio On/Off switch on the control 
top, placing 7.5 Vdc on the B+SENSE line. This voltage enables the pass element Q501 and Q502, 
enabling SW_B+ and GCAP_B+. In NNTN5567 VOCON kit, the B+SENSE line enables the pass 
elements Q500, Q501, and Q503 enabling SW_B+ and RFSW_B+.
When the GCAP II IC U501 detects a low-to-high voltage transition on GCAP_B+, it turns on and 
enables voltage supplies VSW1, VSW2, V2 and Vref. As soon as these voltages come up, the 
1.55 V regulator ramps up (only on the NNTN4717 VOCON board), and the Flipper IC U301 drives 
the WDI line high to enable VCC5 from regulator U505 and to maintain the GCAP II IC in the ON 
state. If WDI remains low, the GCAP II IC turns off 50 ms after turning on. For NNTN5567 VOCON 
board, when the MAKO IC U501 detects a high-to-low transition on the MECH_SW pin, the MAKO 
IC grounds the FET_ENX pin driving the gate of an external P-MOSFET low.  This turns on the 
transistor (Q500) and applies SW_B+ to the MAKO IC and the rest of the board (RF and VoCon). 
After applying power to SW_B+, the regulators VSW1, VSW2, V1.875, V1.55, V_2.9, and VCC5 are 
sequenced on. After the regulators are stable, the RESETX pin is asserted low for an additional 
16ms and then de-asserted allowing the dual-core processor to start.
ABACUS III
U500
(On RF Board)Digital 
LPF =
3.4 kHzCODEC
16-Bit
D/AG1 Digital
Gain = 0 or
1 dB
G3
Attenuator
= -52 to 0
dB
PA
ControlG4
Preamp =
0 to 10
dB
G5
EXT PA
=26 dB
G6
INT PA
=26 dB HP & LP
Filter = 22
kHz, 200 
Hz
Internal
Speaker =
28 ohms
External 
Speaker Patriot
SPIBPatriot
SAP/ BBPMAKO IC U501
PA_IN_M
PA_IN_P VC_OUT_P CODEC_RX
CODEC_DCLK
CODEC_FSYNC
SPI_MOSIB
SCKBMAKO_CS
SPI_MISOB RX_SSI_FSYNC
RX_SSI_CLK
RX_SSI_DATA
VC_OUT_M
33
4