ViewSonic Vx2235wm 5 Service Manual

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3.
 ISP security code 
 
3.1 After installation, we could find the shortcut in the  setting path or the program bar (default setting), see Fig 3.1. 
 
Fig 3.1 
 
2.2 Security file is a key to use ISP function, press “確定 ＂  button, see Fig 3.2. 
 
Fig 3.2 
  

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3.3 The warning is used to remind user of that different CPU rate may cause ISP function fail(it is limited by IIC protocol), 
press  “確定 ＂  button, see Fig 3.3. 
 
Fig 3.3 
 
2.4 Press “Create Security File ＂  button to key in  security code. Adjusting bar to decrease  speed of IIC bus, see Fig 3.4. 
 
Fig 3.4 
  

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3.5 At least 2 Command No of security code, see Fig 3.5, and different security code between hardware ISP and software ISP. 
The security code of software ISP is set by user while coding, but the security code of hardware ISP is set by Myson Century. 
 
Fig 3.5 
  

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3.6  Fig 3.6 shows the setting for security code of  hardware ISP, it needs 4 Command No, and key in command sequentially 
for  94, 94, AC, CA, 53 . 
 
Fig 3.6 
 
 
  

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3.7    Fig 3.7 shows the setting for security code of  software ISP, it needs 2 Command No, and key in command sequentially 
for  7C, 4C, 77 . The Command No and command must be set by user while coding. About the detail of setting, please refer to 
Section 6 Boot code of ISP. 
 
Fig 3.7 
 
  

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4. Use ISP to program MCU 
4.1 Select MTV type first, load the binary or Intel hex 
file that you want to program into the MCU, and select  “Auto ＂ item, 
then press  “RUN ＂  button, see Fig 4.1. 
4.2 If user changes the MTV type, it must load file ag ain, or the buffer of load file will be cleared. 
4.3 CRC (cyclic redundancy check): the host can check CRC register ＇s result instead of reading every byte in flash. The 
message of...

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5 Use ISP to read MCU content 
5.1 Only software ISP could read the MCU content, it is according to program the boot code while coding. The limitation is 
used for the security of customer ＇s code. Select  “Read Target ＂ item, and press “RUN ＂  button, the MCU content 
will show as Fig 5.1. 
 
Fig 5.1 
  

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5.2 If user uses hardware ISP to read MCU content, it shows as Fig 5.2. 
 
Fig 5.2 
  

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6 Re-entry the ISP Mode 
When you could not select or click 
｀Reset MCU ＇  button and enter ISP mode again, you    refer the message as below: 
  

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Note: 
(1)Disable the ｀Enter ISP Mode ＇  option to avoid the error message display. 
(2)If you using the MTV312M64 or before MCU serials, the MCU will always in  ｀ISP Mode ＇even programming fail or 
erase MCU that instead of select or press  ｀Reset MCU ＇.