Philips Semiconductors
Product specification
SCC2698B
Enhanced octal universal asynchronous
receiver/transmitter (Octal UART)
2000 Jan 31
14
Table 2. Register Bit Formats (Continued)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
CSR (Clock Select Register)
Receiver Clock Select
Transmitter Clock Select
See text
* See Table 5 for BRG Test frequencies in this data sheet, and
“Extended baud rates for SCN2681, SCN68681, SCC2691, SCC2692,
SCC68681 and SCC2698B” Philips Semiconductors ICs for Data Communications, IC-19, 1994.
OPCR (Output Port Configuration Register) This register controls the MPP I/O pins and the MPO multi-purpose output pins.
MPP Function
Select
MPOb Pin Function Select
Power-Down
Mode*
MPOa Pin Function Select
0 = input
000 = RTSN
0 = Off
000 = RTSN
1 = output
001 = C/TO
1 = On
001 = C/TO
010 = TxC (1X)
011 = TxC (16X)
100 = RxC (1X)
101 = RxC (16X)
110 = TxRDY
111 = RxRDY/FF
NOTE: *Only OPCR[3] in block A controls the power-down mode.
ACR (Auxiliary Control Register)
BRG Select
Counter/Timer Mode and Source
Delta
MPI1bINT
Delta
MPI0bINT
Delta
MPI1aINT
Delta
MPI0aINT
0 = set 1
1 = set 2
See Text
0 = off
1 = on
0 = off
1 = on
0 = off
1 = on
0 = off
1 = on
IPCR (Input Port Change Register)
Delta MPI1b
Delta MPI0b
Delta MPI1a
Delta MPI0a
MPI1b
MPI0b
MPI1a
MPI0a
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
0 = Low
1 = High
0 = Low
1 = High
0 = Low
1 = High
0 = Low
1 = High
ISR (Interrupt Status Register)
MPI Port
Change
Delta BREAKb
RxRDY/
FFULLb
TxRDYb
Counter
Ready
Delta BREAKa
RxRDY/
FFULLa
TxRDYa
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
IMR (Interrupt Mask Register)
MPI Port
Change INT
Delta BREAKb
INT
RxRDY/
FFULLb INT
TxRDYb INT
Counter
Ready INT
Delta BREAKa
INT
RxRDY/
FFULLa INT
TxRDYa INT
0 = off
1 = on
0 = off
1 = on
0 = off
1 = on
0 = off
1 = on
0 = off
1 = on
0 = off
1 = on
0 = off
1 = on
0 = off
1 = on
CTPU (Counter/Timer Upper Register)
C/T[15]
C/T[14]
C/T[13]
C/T[12]
C/T[11]
C/T[10]
C/T[9]
C/T[8]
CTPU (Counter/Timer Lower Register)
C/T[7]
C/T[6]
C/T[5]
C/T[4]
C/T[3]
C/T[2]
C/T[1]
C/T[0]
IPR (Input Port Register) MPP and MPI Pins
MPP2b
MPP1b
MPP2a
MPP1a
MPI1b
MPI0b
MPI1a
MPI0a
0 = Low
1 = High
0 = Low
1 = High
0 = Low
1 = High
0 = Low
1 = High
0 = Low
1 = High
0 = Low
1 = High
0 = Low
1 = High
0 = Low
1 = High
NOTE: When TxEMT and TxRDY bits are at one just before a write to the Transmit Holding register, a command to disable the transmitter
should be delayed until the TxRDY is at one again. TxRDY will set to one at the end of the start bit time.