tlfong01 fongtoy ft2077 troubleshooting notes

Now I am checking out the signal waveforms at the EEPROM side.


    EePromCommandWriteLatchEnable    = 0x06

    # *** Enable Write Enable Latch ***
    while True:
        spiEeprom.xfer2([EePromCommandWriteLatchEnable]) 



def Test25Lc256():

    PrintDoubleSpaceLine("*** Start testing 25LC256 ***")   

    # *** Set up SPI channel ***  
    # import spidev # WiringPi Python wrapper
    # spidev.max_speed_hz = 10000 # seems no effect, clock always 2 MHz !!!
    spiEeprom = spidev.SpiDev() 
    spiEeprom.open(0, 0)  

    # *** 25LC256 instructions ***
    EepromCommandWriteStatusRegister = 0x01
    EepromcCommandWrite              = 0x02 
    EePromCommandRead                = 0x03 
    EepromCommandWriteLatchDisable   = 0x04
    EepromCommandReadStatusRegister  = 0x05
    EePromCommandWriteLatchEnable    = 0x06 

    # *** 25LC256 addresses ***
    #EepromStartAddress0= 0x0000
    #EepromStartAddressUpper0 = 0x00
    #EepromStartAddressLower0 = 0x00

    EepromStartAddress1= 0x0300
    EepromStartAddressUpper1 = 0x03
    EepromStartAddressLower1 = 0x00

    # *** SPI variables and constants ***

    writeSpiDataList = [0x00]
    readSpiDataList  = [0x00, 0x00, 0x00, 0x00, 0x00]

    DummyDataByte = 0x00
    TestDataByte55  = 0x55
    TestDataByteAa  = 0xaa

    WriteProtectNone        = 0x00 # -
    WriteProtectUpperFourth = 0x04 # 0x6000 to 0x7fff
    WriteProtectUpperHalf   = 0x08 # 0x4000 to 0x7fff
    WriteProtectAll         = 0x0c # 0x0000 to 0x7fff

    FiveMilliSeconds = 0.005
  
    # *** Enable Write Enable Latch ***
    while True:
        spiEeprom.xfer2([EePromCommandWriteLatchEnable]) 
    
    time.sleep(FiveMilliSeconds)


    # *** Read Status Register ***
    readSpiDataList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking WEL bit after Write Enable ***")  
    PrintEightBitPattern("Read back byte 0 = ", readSpiDataList[0])
    PrintEightBitPattern("Read back byte 1 = ", readSpiDataList[1])
    time.sleep(FiveMilliSeconds)

    # *** Disable Write Enable Latch ***
    spiEeprom.xfer2([EepromCommandWriteLatchDisable]) 
    time.sleep(FiveMilliSeconds)

    # *** Check WEL (Write Enable Latch) bit (Bit 1) ***
    readInByteList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking WEL bit after Write Disable ***")  
    PrintEightBitPattern("Read back byte 0 = ", readInByteList[0])
    PrintEightBitPattern("Read back byte 1 = ", readInByteList[1])
    time.sleep(0.005)

    # *** Write Enable ***
    spiEeprom.xfer2([EePromCommandWriteLatchEnable]) 
    time.sleep(0.005)

    # *** Check WEL (Write Enable Latch) bit (Bit 1) ***
    readInByteList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking WEL bit after Write Enable ***")  
    PrintEightBitPattern("Read back byte 0 = ", readInByteList[0])
    PrintEightBitPattern("Read back byte 1 = ", readInByteList[1])
    time.sleep(0.005)

    # *** Write protect upper fourth ****
    spiEeprom.xfer2([EepromCommandWriteStatusRegister, WriteProtectUpperFourth])
    time.sleep(0.005)

    # *** Check Status Register ***
    readInByteList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking Write Protect Bits ***")  
    PrintEightBitPattern("Read back byte 0 = ", readInByteList[0])
    PrintEightBitPattern("Read back byte 1 = ", readInByteList[1])
    time.sleep(0.005)

    # *** Write Enable ***
    spiEeprom.xfer2([EePromCommandWriteLatchEnable]) 
    time.sleep(0.005)

    # *** Write protect none ****
    spiEeprom.xfer2([EepromCommandWriteStatusRegister, WriteProtectNone])
    time.sleep(0.005)

    # *** Check Status Register ***
    readInByteList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking Write Protect Bits ***")  
    PrintEightBitPattern("Read back byte 0 = ", readInByteList[0])
    PrintEightBitPattern("Read back byte 1 = ", readInByteList[1])
    time.sleep(0.005)

    # *** Write Enable ***
    spiEeprom.xfer2([EePromCommandWriteLatchEnable]) 
    time.sleep(0.005)

    # *** Write 2 data bytes at address 0x0000 ****
    spiEeprom.xfer2([EepromcCommandWrite, EepromStartAddressUpper1, EepromStartAddressLower1, TestDataByte55, TestDataByte55]) 

    # *** Check WIP (Write In Progress) bit (Bit 0) ***
    readInByteList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking WIP bit immediately after writing 1 byte without waiting 5 mS ***")  
    PrintEightBitPattern("Read back byte 0 = ", readInByteList[0])
    PrintEightBitPattern("Read back byte 1 = ", readInByteList[1]) 
    time.sleep(0.005)

    # *** Check WIP (Write In Progress) bit (Bit 0) ***
    readInByteList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking WIP bit again, after waiting 5 mS ***")  
    PrintEightBitPattern("Read back byte 0 = ", readInByteList[0])
    PrintEightBitPattern("Read back byte 1 = ", readInByteList[1])

    # *** Enable Write Enable Latch ***
    spiEeprom.xfer2([EePromCommandWriteLatchEnable]) 
    time.sleep(FiveMilliSeconds)

    # *** Read back data at address 0x0000 ***
    
    readSpiDataList = spiEeprom.xfer2([EePromCommandRead, EepromStartAddressUpper1, EepromStartAddressLower1, DummyDataByte, DummyDataByte])   
    
    PrintDoubleSpaceLine("*** Read back data byte written ***")  
    PrintEightBitPattern("Read back byte 0 = ", readSpiDataList[0])
    PrintEightBitPattern("Read back byte 1 = ", readSpiDataList[1])
    PrintEightBitPattern("Read back byte 2 = ", readSpiDataList[2])
    PrintEightBitPattern("Read back byte 3 = ", readSpiDataList[3]) 
    PrintEightBitPattern("Read back byte 4 = ", readSpiDataList[4]) 


    # *** Write Enable ***
    spiEeprom.xfer2([EePromCommandWriteLatchEnable]) 
    time.sleep(0.005)

    # *** Write 2 data bytes at address 0x0000 ****
    spiEeprom.xfer2([EepromcCommandWrite, EepromStartAddressUpper1, EepromStartAddressLower1, TestDataByteAa, TestDataByteAa]) 

    # *** Check WIP (Write In Progress) bit (Bit 0) ***
    readInByteList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking WIP bit immediately after writing 1 byte without waiting 5 mS ***")  
    PrintEightBitPattern("Read back byte 0 = ", readInByteList[0])
    PrintEightBitPattern("Read back byte 1 = ", readInByteList[1]) 
    time.sleep(0.005)

    # *** Check WIP (Write In Progress) bit (Bit 0) ***
    readInByteList = spiEeprom.xfer2([EepromCommandReadStatusRegister, DummyDataByte]) 
    PrintDoubleSpaceLine("*** Checking WIP bit again, after waiting 5 mS ***")  
    PrintEightBitPattern("Read back byte 0 = ", readInByteList[0])
    PrintEightBitPattern("Read back byte 1 = ", readInByteList[1])

    # *** Enable Write Enable Latch ***
    spiEeprom.xfer2([EePromCommandWriteLatchEnable]) 
    time.sleep(FiveMilliSeconds)

    # *** Read back data at address 0x0000 ***
    
    readSpiDataList = spiEeprom.xfer2([EePromCommandRead, EepromStartAddressUpper1, EepromStartAddressLower1, DummyDataByte, DummyDataByte])   
    
    PrintDoubleSpaceLine("*** Read back data byte written ***")  
    PrintEightBitPattern("Read back byte 0 = ", readSpiDataList[0])
    PrintEightBitPattern("Read back byte 1 = ", readSpiDataList[1])
    PrintEightBitPattern("Read back byte 2 = ", readSpiDataList[2])
    PrintEightBitPattern("Read back byte 3 = ", readSpiDataList[3]) 
    PrintEightBitPattern("Read back byte 4 = ", readSpiDataList[4])    
    
    # *** Close SPI channel ***
    spiEeprom.close() 

    #while True:
    #    pass

    PrintDoubleSpaceLine("*** Stop testing write/read 25LC256 ***") 

.END