~ National ~ Semiconductor - Al Kossow's Bitsavers

7.0 CPU Registers (Continued)
BIT INDEX
An alphabetical listing of all status/control bits in the CPU-addressable special function registers, with a brief summary of
function. Detailed definitions are provided in the Bit Definition Table.
Bit Name Location Function
ACK poll/ACKnowledge NCF [1] Receiver Status
ASP3-0 Address Stack Pointer ISP [7-4] Stacks
AT7-0 Auxilliary Transceiver control ATR [7-0] Receiver Control
ATA Advance Transmitter Active TCR [4] Transmitter Control
BIC Bi-directionallnterrupt Control ACR [4] Interrupt Control
BIRQ Bi-directionallnterrupt ReQuest CCR [4] Interrupt Control
C Carry CCR [1] Arithmetic Flag
CCS CPU Clock Select OCR [7] Timing Control
COD Clock Out Disable ACR [2] Timing Control
DAV Data AVailable TSR [3] Receiver Status
DEME Data Error or Message End NCF [3] Receiver Status
DS7-0 Data Stack OS [7-0] Stacks
DSP3-0 Data Stack Pointer ISP [3-0] Stacks
DW2-0 Data memory Wait-state select OCR [2-0] Timing Control
FB7-0 Fill Bits FBR [7-0] Transmitter Control
GIE Global Interrupt Enable ACR [0] Interrupt Control
IES Invalid Ending Sequence ECR [2] Receiver Error Code
IM4-0 Interrupt Mask select ICR [4-0] Interrupt Control
IV15-8 Interrupt Vector IBR [7-0] Interrupt Control
IW1,0 Instruction memory Wait-state select OCR [4,3] Timing Control
LA Line Active NCF [5] Receiver Status
LMBT Loss of Mid Bit Transition ECR [1] Receiver Error Code
LOR Lock Out Remote ACR [1] Remote Interface
LOOP internal LOOP-back TMR [6] Transceiver Control
LTA Line Turn Around NCF [4] Receiver Status
N Negative CCR [3] Arithmetic Flag
OVF receiver OVerFlow ECR [4] Receiver Error Code
OWP Odd Word Parity TCR [3] Transmitter Control
PAR PARity error ECR [3] Receiver Error Code
POLL POLL NCF [0] Receiver Status
PS2-0 Protocol Select TMR [2-0] Transceiver Control
RA Receiver Active TSR [4] Receiver Status
RAR Received Auto-Response NCF [2] Receiver Status
RDIS Receiver DISabled while active ECR [0] Receiver Error Code
RE Receiver Error TSR [5] Receiver Status
RF10-8 Receiver FIFO TSR [2-0] Receiver Control
RFF Receive FIFO Full NCF [6] Receiver Status
RIN Receiver INvert TMR [4] Receiver Control
RIS1,0 Receiver Interrupt Select ICR [7,6] Interrupt Control
RLQ Receive Line Quiesce TCR [7] Receiver Control
RPEN RePeat ENable TMR [5] Receiver Control
RR Remote Read CCR [6] Remote Interface
RTF7-0 Receive/Transmit FIFO RTR [7-0] Transceiver Control
RW Remote Write CCR [5] Remote Interface
SEC Select Error Codes TCR [6] Receiver Control
SLR Select Line Receiver TCR [5] Receiver Control
TA Transmitter Active TSR [6] Transmitter Status
TCS1,0 Transceiver Clock Select OCR [6,5] Transceiver Control
TF10-8 Transmit FIFO TCR [2-0] Transmitter Control
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