TL16C752

3.3-V DUAL UART WITH 64-BYTE FIFO

SLLS305 – MAY 1999

31

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

TL16C752 programmer’s guide

The base set of registers that is used during high speed data transfer have a straightforward access method.

The extended function registers require special access bits to be decoded along with the address lines. The

following guide will help with programming these registers. Note that the descriptions below are for individual

register access. Some streamlining through interleaving can be obtained when programming all the registers.

Set baud rate to VALUE1, VALUE2

Read LCR (03), save in temp

Set LCR (03) to 80

Set DLL (00) to VALUE1

Set DLM (01) to VALUE2

Set LCR (03) to temp

Set Xoff1, Xon1 to VALUE1, VALUE2

Read LCR (03), save in temp

Set LCR (03) to BF

Set Xoff1 (06) to VALUE1

Set Xon1 (04) to VALUE2

Set LCR (03) to temp

Set Xoff2, Xon2 to VALUE1, VALUE2

Read LCR (03), save in temp

Set LCR (03) to BF

Set Xoff2 (07) to VALUE1

Set Xon2 (05) to VALUE2

Set LCR (03) to temp

Set software flow control mode to VALUE

Read LCR (03), save in temp

Set LCR (03) to BF

Set EFR (02) to VALUE

Set LCR (03) to temp

Set flow control threshold to VALUE

Read LCR (03), save in temp1

Set LCR (03) to BF

Read EFR (02), save in temp2

Set EFR (02) to 10 + temp2

Set LCR (03) to 00

Read MCR (04), save in temp3

Set MCR (04) to 40 + temp3

Set TCR (06) to VALUE

Set LCR (03) to BF

Set EFR (02) to temp2

Set LCR (03) to temp1

Set MCR (04) to temp3

Set xmt and rcv FIFO thresholds to VALUE

Read LCR (03), save in temp1

Set LCR (03) to BF

Read EFR (02), save in temp2

Set EFR (02) to 10 + temp2

Set LCR (03) to 00

Read MCR (04), save in temp3

Set MCR (04) to 40 + temp3

Set TLR (07) to VALUE

Set LCR (03) to BF

Set EFR (02) to temp2

Set LCR (03) to temp1

Set MCR (04) to temp2

Read FIFORdy register

Read MCR (04), save in temp1

Set temp2 = temp1

× EF

Set MCR (04) = 04 + temp2

Read FRR (07), save in temp2

Pass temp2 back to host

Set MCR (04) to temp1