I have reviewed the datasheet regarding wetting this part into 64 byte FIFO mode. We are polling the part, and the baud is 115.2k, 1 start, no parity 2 stop, and 8 data.
Our code currently has LCR MSB=0 before these two writes to FCR:
FCR = 0xF1
1msec delay
FCR = 0xF7
When reading back FCR we read 0xC1, so bit 5 is not set when LCR MSB = 0
on page 23 of datasheet: Access to FCR bit 5 require LCR bit 7 = 1, on page 24, in Bit 5: A write to FCR bit 5 is protected by setting the line control register(LCR) bit7 = 1. This is ambiguous.
I have also tried:
LCR = 0x80
FCR = 0x1
FCR = 0x21
then used the existing code
LCR = 7
FCR = 0xF1
1msec delay
FCR = 0xF7
But again bit 5 is not set. Is the FCR register able to read all the bits, because what was read back was 0x12.
Please advise to the correct procedure to writing to this register, reading it, and especially setting bit 5.
Thanks,