Register Descriptions
A-13
Register Summary
Asynchronous Serial Port Control Register (ASPCR) — I/O Address FFF5h
15 14 13 12 11 10 9 8
0 0 0 0 0 0
FREE SOFT URST ReservedDIM TIM
Immediate stop
Process stops after character completion.
Free run
Free run
0
1Port in reset
Port enabled Disables transmit interrupts
Enables transmit interrupts
0
1Disables delta interrupts
Enables delta interrupts
0
1
0
1
0
1
0
0
1
1
Emulation/run mode
R/WR/W R/W R/W R/W
Port reset
Delta interrupt mask
Transmit interrupt mask
7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0
RIM STB CAD SETBRK CIO3 CIO2 CIO1 CIO0
0
1Disables receive interrupts
Enables receive interrupts
0
1One stop bit for transmission and reception
Two stop bits for transmission and reception
0
1Disables auto-baud alignment
Enables auto-baud alignment when ADC = 0
0
1TX output forced high
TX output forced low
0
1IO3 configured as input
IO3 configured as output
0
1IO2 configured as input
IO2 configured as output
0
1IO1 configured as input
IO1 configured as output
0
1IO0 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.