Toppcstack - Analog Devices adsp-2100 Manual

Syntax Status Condition
EQ Equal Zero
NE Not Equal Zero
LT Less Than Zero
GE Greater Than or Equal Zero AN .XOR. AV = 0
LE Less Than or Equal Zero
GT Greater Than Zero
AC ALU Carry
NOT AC Not ALU Carry
AV ALU Overflow
NOT AV Not ALU Overflow
MV MAC Overflow
NOT MV Not MAC Overflow
NEG X Input Sign Negative
POS X Input Sign Positive
NOT CE Not Counter Expired
FLAG_IN* FI pin
NOT FLAG_IN* Not FI pin
* Only available on JUMP and CALL instructions.
Table 3.9 IF Condition Logic
3.7

TOPPCSTACK

A special version of the Register-to-Register Move instruction, Type 17, is
provided for reading (and popping) or writing (and pushing) the top
value of the PC stack. The normal POP PC instruction does not save the
value popped from the stack, so to save this value into a register you must
use the following special instruction:
reg = TOPPCSTACK;
lowercase}
The PC stack is also popped by this instruction, after a one-cycle delay.
A NOP should usually be placed after the special instruction, to allow the
pop to occur properly:
reg = TOPPCSTACK;
NOP;
Program Control
{pop PC stack into reg}
{"toppcstack" may also be
{allow pop to occur correctly}
True If:
AZ = 1
AZ = 0
AN .XOR. AV = 1
(AN .XOR. AV) .OR. AZ = 1
(AN .XOR. AV) .OR. AZ = 0
AC = 1
AC = 0
AV = 1
AV = 0
MV = 1
MV = 0
AS = 1
AS = 0
—
Last sample of FI pin = 1
Last sample of FI pin = 0
3
3 – 25