Owner manual

62
AT76C551
1612D–08/01
UART Register Set
In Table 10, the register file and its fields are briefly presented. A more detailed description is provided in the following
sections.
Table 10. UART Register File and Register Fields
Addr.
(hex) Register Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
700000US_RHRX XXXXXXX
700000US_THRX XXXXXXX
700004 US_IER Transmitter
empty
interrupt
Receive
time-out
interrupt
Parity
error
interrupt
Framing
error
interrupt
Overrun
error
interrupt
Receive
break
interrupt
Transmit
holding
register
Receive
holding
register
700008 US_FCR RCVR
trigger
(MSB)
RCVR
trigger
(LSB)
00DMA
mode
select
0 RCVR
FIFO
reset
FIFO
enable
70000C US_PMR Character
length
(MSB)
Character
length
(MSB)
Number of
stop bits
(MSB)
Number of
stop bits
(LSB)
Parity
mode
(PTM2)
Parity
mode
(PTM1)
Parity
type
(PT)
0
700010 US_MR Channel
mode
(CHM1)
Channel
mode
(CHM0)
000000
700014 US_CSR Transmitter
empty
Receive
time-out
Parity
error
Framing
error
Overrun
error
Receive
break
Transmit
holding
register
ready
Receive
holding
register
ready
700018 US_CR Rx
enable
Reset
status bit
Tx enable Restart
time-out
Tx
teset
Rx
teset
Stop
break
Start
break
70001C US_BL MSB LSB
700020 US_BM MSB LSB
700024 US_RTO MSB LSB
700028 US_TTG MSB LSB
70002C US_MCI DSR RI CD CTS DSR
change
RI change CD
change
CTS
change
70002CUS_MCO0 00000RTSDTR
700030 US_MCC 0 LB RI
value
LB CD
value
MC Loop
back
enable
DSR
change
mask
RI change
mask
CD
change
mask
CTS
change
mask