BCM1250/BCM1125/BCM1125H
User Manual
10/21/02
B r o a d c o m C o r p o r a t i o n
Page
326
Section 10: Serial Interfaces
Document
1250_1125-UM100CB-R
DUART R
EGISTERS
Table 197: DUART Mode Registers
duart_mode_reg_1_a -
00_1006_0100
duart_mode_reg_1_b -
00_1006_0200
Bits
Name
Default
Description
1:0
duart_bits_per_char
2'b00
0: 8
1: Reserved
2: 7
3: 8
2
duart_parity_type
1'b0
Parity type:
0: Even/Low
1: Odd/High
4:3
duart_parity_mode
2'b0
Parity mode.
0: Add Parity (even/odd selected by bit 2)
1: Add fixed parity bit (low/high selected by bit 2)
2: No Parity
3: No Parity
5
duart_tx_irq_sel
1'b0
Transmitter interrupt select.
0: Interrupt when the transmitter is ready (there is space in the fifo for at least
one character).
1: Interrupt when the transmit fifo is empty.
6
duart_rx_irq_sel
1'b0
Receiver Interrupt select.
0: Interrupt on receiver ready (at least one character in the FIFO).
1: Interrupt on receiver FIFO full
7
duart_rx_rts_ena
1'b0
Receiver Request-to-Send Control enable.
Channel A: If set the S0_RTS_TSTROBE pin will be used as hardware
controlled RTS, if clear the pin will output the inverse of op[0].
Channel B: If set the S1_RTS_TSTROBE pin will be used as hardware
controlled RTS, if clear the pin will output the inverse of op[1].
63:8 notimp
56’bx
Not implemented.
Table 198: DUART Second Mode Registers
duart_mode_reg_2_a -
00_1006_0110
duart_mode_reg_2_b -
00_1006_0210
Bits
Name
Default
Description
2:0
ignored
3'b000
These bits are ignored.
3
duart_stop_bit_len
1'b0
Set for 2 Stop bits, clear for 1 stop bit
4
duart_tx_cts_ena
1'b0
Set to cause the transmitter to check CTS, clear to ignore CTS.
Channel A CTS is on the S0_CTS_TCLKIN pin and is also readable as ip[0].
Channel B CTS is on the S1_CTS_TCLKIN pin and is also readable as ip[1].
5
reserved
1'b0
Always 0
7:6
duart_chan_mode
2'b00
Channel Mode.
0: Normal
1: Normal
2: Local loopback
3: Remote loopback
63:8
notimp
56’bx
Not implemented.