TL16C752B-EP

3.3-V DUAL UART WITH 64-BYTE FIFO

SGLS153 – FEBRUARY 2003

32

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PRINCIPLES OF OPERATION

FIFO ready register (continued)

Table 20. FIFO Ready Register

BIT NO.

BIT SETTINGS

0

0 = There are less than a TX trigger level number of spaces available in the TX FIFO of channel A.

1 = There are at least a TX trigger level number of spaces available in the TX FIFO of channel A.

1

0 = There are less than a TX trigger level number of spaces available in the TX FIFO of channel B.

1 = There are at least a TX trigger level number of spaces available in the TX FIFO of channel B.

3:2

Unused, always 0

4

0 = There are less than a RX trigger level number of characters in the RX FIFO of channel A.

1 = The RX FIFO of channel A has more than a RX trigger level number of characters available for reading or a timeout condition

has occurred.

5

0 = There are less than a RX trigger level number of characters in the RX FIFO of channel B.

1 = The RX FIFO of channel B has more than a RX trigger level number of characters available for reading or a timeout condition

has occurred.

7:6

Unused, always 0

The FIFORdy register is a read-only register that can be accessed when any of the two UARTs are selected

CSA-B = 0, MCR[2] (FIFO Rdy Enable) is a logic 1 and loopback is disabled. The address is 111.

TL16C752B-EP 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 helps 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