Philips Semiconductors
Product specification
SCC2692
Dual asynchronous receiver/transmitter (DUART)
1998 Sep 04
11
Table 1.
SCC2692 Register Addressing
A3
A2
A1
A0
READ (RDN = 0)
WRITE (WRN = 0)
0
Mode Register A (MR1A, MR2A)
0
1
Status Register A (SRA)
Clock Select Register A (CSRA)
0
1
0
BRG Test
Command Register A (CRA)
0
1
Rx Holding Register A (RHRA)
Tx Holding Register A (THRA)
0
1
0
Input Port Change Register (IPCR)
Aux. Control Register (ACR)
0
1
0
1
Interrupt Status Register (ISR)
Interrupt Mask Register (IMR)
0
1
0
Counter/Timer Upper Value (CTU)
C/T Upper Preset Value (CRUR)
0
1
Counter/Timer Lower Value (CTL)
C/T Lower Preset Value (CTLR)
1
0
Mode Register B (MR1B, MR2B)
1
0
1
Status Register B (SRB)
Clock Select Register B (CSRB)
1
0
1
0
1X/16X Test
Command Register B (CRB)
1
0
1
Rx Holding Register B (RHRB)
Tx Holding Register B (THRB)
1
0
Reserved
1
0
1
Input Ports IP0 to IP6
Output Port Conf. Register (OPCR)
1
0
Start Counter Command
Set Output Port Bits Command
1
Stop Counter Command
Reset Output Port Bits Command
* See Table 6 for BRG Test frequencies in this data sheet, and
“Extended baud rates for SCN2681, SCN68681, SCC2691, SCC2692,
SCC68681 and SCC2698B” in application notes elsewhere in this publication
Table 2.
Register Bit Formats
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
MR1A
RxRTS
CONTROL
RxINT
SELECT
ERROR
MODE*
PARITY MODE
PARITY
TYPE
BITS PER
CHARACTER
MR1A
MR1B
0 = No
1 = Yes
0 = RxRDY
1 = FFULL
0 = Char
1 = Block
00 = With Parity
01 = Force Parity
10 = No Parity
11 = Multidrop Mode
0 = Even
1 = Odd
00 = 5
01 = 6
10 = 7
11 = 8
NOTE:
*In block error mode, block error conditions must be cleared by using the error reset command (command 4x) or a receiver reset.
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
MR2A
CHANNEL MODE
TxRTS
CONTROL
CTS
ENABLE Tx
STOP BIT LENGTH*
MR2A
MR2B
00 = Normal
01 = Auto-Echo
10 = Local loop
11 = Remote loop
0 = No
1 = Yes
0 = No
1 = Yes
0 = 0.563
4 = 0.813
8 = 1.563
C = 1.813
1 = 0.625
5 = 0.875
9 = 1.625
D = 1.875
2 = 0.688
6 = 0.938
A = 1.688
E = 1.938
3 = 0.750
7 = 1.000
B = 1.750
F = 2.000
NOTE: *Add 0.5 to values shown for 0 – 7 if channel is programmed for 5 bits/char.
CSRA
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
CSRA
CSRB
RECEIVER CLOCK SELECT
TRANSMITTER CLOCK SELECT
CSRB
See Text
* See Table 6 for BRG Test frequencies in this data sheet, and
“Extended baud rates for SCN2681, SCN68681, SCC2691, SCC2692,
SCC68681 and SCC2698B” in application notes elsewhere in this publication
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
CRA
CRB
MISCELLANEOUS COMMANDS
DISABLE Tx
ENABLE Tx
DISABLE Rx
ENABLE Rx
CRB
See Text and Timing Requirement
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
0 = No
1 = Yes
NOTE: Access to the miscellaneous commands should be separated by 3 X1 clock edges. A disabled transmitter cannot be loaded.