Register Descriptions
A-13
Register Summary
Asynchronous Serial Port Control Register (ASPCR) — I/O Address FFF5h
ÁÁ
ÁÁ
ÁÁÁÁ
ÁÁÁÁ
15
ÁÁÁÁÁ
ÁÁÁÁÁ
14
ÁÁÁÁ
ÁÁÁÁ
13
ÁÁÁÁÁ
ÁÁÁÁÁ
12
ÁÁÁÁÁ
ÁÁÁÁÁ
11
ÁÁÁÁ
ÁÁÁÁ
10
ÁÁÁÁÁ
ÁÁÁÁÁ
9
ÁÁÁÁ
ÁÁÁÁ
8
ÁÁ
ÁÁ
ÁÁ
ÁÁ
ÁÁÁÁ
ÁÁÁÁ
0
ÁÁÁÁÁ
ÁÁÁÁÁ
0
ÁÁÁÁ
ÁÁÁÁ
0
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
0
ÁÁÁÁÁ
ÁÁÁÁÁ
0
ÁÁÁÁ
ÁÁÁÁ
0
ÁÁ
ÁÁ
FREE
SOFT
URST
Reserved
†
DIM
TIM
Immediate stop
Process stops after character completion.
Free run
Free run
0
1
Port in reset
Port enabled
Disables transmit interrupts
Enables transmit interrupts
0
1
Disables delta interrupts
Enables delta interrupts
0
1
0
1
0
1
0
0
1
1
Emulation/run mode
R/W
R/W
R/W
R/W
R/W
Port reset
Delta interrupt mask
Transmit interrupt mask
ÁÁ
ÁÁ
ÁÁ
ÁÁÁÁ
Á
ÁÁ
Á
ÁÁÁÁ
7
ÁÁÁÁÁ
Á
ÁÁÁ
Á
ÁÁÁÁÁ
6
ÁÁÁÁ
Á
ÁÁ
Á
ÁÁÁÁ
5
ÁÁÁÁÁ
Á
ÁÁÁ
Á
ÁÁÁÁÁ
4
ÁÁÁÁÁ
Á
ÁÁÁ
Á
ÁÁÁÁÁ
3
ÁÁÁÁ
Á
ÁÁ
Á
ÁÁÁÁ
2
ÁÁÁÁÁ
Á
ÁÁÁ
Á
ÁÁÁÁÁ
1
ÁÁÁÁ
Á
ÁÁ
Á
ÁÁÁÁ
0
ÁÁ
ÁÁ
ÁÁ
ÁÁ
ÁÁ
ÁÁÁÁ
ÁÁÁÁ
0
ÁÁÁÁÁ
ÁÁÁÁÁ
0
ÁÁÁÁ
ÁÁÁÁ
0
ÁÁÁÁÁ
ÁÁÁÁÁ
0
ÁÁÁÁÁ
ÁÁÁÁÁ
0
ÁÁÁÁ
ÁÁÁÁ
0
ÁÁÁÁÁ
ÁÁÁÁÁ
0
ÁÁÁÁ
ÁÁÁÁ
0
ÁÁ
ÁÁ
RIM
STB
CAD
SETBRK
CIO3
CIO2
CIO1
CIO0
0
1
Disables receive interrupts
Enables receive interrupts
0
1
One stop bit for transmission and reception
Two stop bits for transmission and reception
0
1
Disables auto-baud alignment
Enables auto-baud alignment when ADC = 0
0
1
TX output forced high
TX output forced low
0
1
IO3 configured as input
IO3 configured as output
0
1
IO2 configured as input
IO2 configured as output
0
1
IO1 configured as input
IO1 configured as output
0
1
IO0 configured as input
IO0 configured as output
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Receive interrupt mask
Number of stop bits
Auto-baud alignment
TX pin level between transmissions
IO3 pin configuration
IO2 pin configuration
IO1 pin configuration
IO0 pin configuration
† These reserved bits are always read as 0s. Writes have no effect.