Legend

Symbol

Meaning

 

 

nR

Value in repeat counter loaded by RPT instructions

ns

Value in string register STR

OF

Overflow flag

 

 

offset[n]

n bit offset from a reference register.

 

 

OM

Overflow mode

 

 

PC

Program counter, 16 bits

 

 

pma[n]

n bit program memory address. For example, pma8 means 8-bit program memory address. If n is

 

not specified, defaults to pma16.

 

 

port[n]

n bit I/O port address. Certain instructions multiply this port address by 4.

 

 

PH

Product high register, 16 bits

 

 

PL

Product low register, 16 bits (cannot be read/written directly)

RRx register treated as a general purpose register. This bit is not related to any addressing mode.

RCF

Register carry flag

 

 

Rx

Indirect register x where x = 0..7

 

 

RZF

Register zero flag

sRepresents string mode if 1, otherwise normal mode.

SF

Sign flag

 

 

STAT

Status register, 17 bits

 

 

STR

String register, 8 bits

 

 

SV

Shift value register, 4 bits

 

 

TAG

Memory tag

 

 

TF1

Test flag 1

 

 

TF2

Test flag 2

 

 

TOS

Top of stack register, 16 bits

 

 

UM

Unsigned mode

wWord(s) taken by instruction

xDon’t care

XM

Extended sign mode

 

 

XSF

Transfer (TX) sign flag

 

 

XZF

Transfer (TX) zero flag

 

 

ZF

Zero flag

 

 

4-72

Page 158
Image 158
Texas Instruments MSP50C6xx manual Offset n, Pma n, Port n