Tandy 1000 HX Technical Reference Manual page 176

Instruction Set (cont)
Mnemonic
Subroutine
Registers
DEC Rr (Rr)
INCRr
INC@Rr
Function
(Rr) — ( R r ) - 1; r =
(Rr) — (Rr) + 1; r =
((Rr)) — ((Rr)) + 1;
r = 0-1
0-7
= 0-7
Description
Decrement by 1 contents of designated register.
Increment by 1 contents of designated register.
Increment indirect by 1 the contents of data memory location.
D
7
1
0
0
D
e
1
0
0
D.
0
0
0
Operation Code
i
D
4
0
1
1
D
3
D
2
1 r
1 r
0 0
D
1
r
r
0
Do
r
r
r
Cycles
1
1
1
Bytes
1
1
1
Flags
C AC FO F1
CALLaddr ((SP)) — (PC),
(PSW4-PSW7),
(SP) * - (SP) + 1
(PC
8
-PC
10
) — (addr
8
-addr
10
)
(PC0-PC7) — (addr
o
-addr
7
)
(PCn) — D B F
Call designated subroutine. 1 0 1
a
5
a
4
a
3
a
2
RET
RETR
Timer/Counter
EN TCNTI
DISTCNTI
MOV A, T
MOV T, A
STOPTCNT
STRT CNT
STRTT
Miscellaneous
NOP
(SP) — (SP) = 1
(PC) —((SP))
(SP) — ( S P ) = 1
(PC) —((SP))
(PSW4-PSW7) — ((SP))
(A) — ( T )
(T) — ( A )
Return from subroutine without restoring program status word.
Return from subroutine restoring program status word.
Enable internal interrupt flag for timer / counter output.
Disable internal interrupt flag for timer / counter output.
Move contents of timer / counter into accumulator.
Move contents of accumulator into timer / counter.
Stop count for event counter.
Start count for event counter.
Start count for timer.
No operation performed.
1
1
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
1
1
0
1
1
0
0
0
0
1
0
1
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
1
1
1
0
1
1
0
0
1
1
0
0
0
0
1
1
1
1
0
0
1
1
1
0
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Note:
(1) Operation code designations r and p form the binary representation of the registers and ports involved.
(2) The dot under the appropriate flag bit indicates that its content is subject to change by the instruction it appears in.
(3) References to the address and data are specified in bytes 2 and/or 1 of the instruction.
(4) Numerical subscripts appearing in the function column reference the specific bits affected.
(5) When the bus is written to, with an OUTL instruction, the bus remains an output port until either device is reset or a MOVX instruction is excecuted.