~ National ~ Semiconductor - Al Kossow's Bitsavers

~ ,--------------------------------------------------------------------,
~
~
CO)
~
c
6.0 Instruction Set Reference (Continued)
ADCA
Syntax
ADCA
ADCA
Add with Carry and Accumulator
Rs, Rd
Rs, [mlr]
Affected Flags
N,Z,C, V
Description
-register, register
-register, indexed
Adds the source register Rs, the active accumulator, and
the carry flag together, placing the result into the destination
specified. The destination may be either a register, Rd, or
data memory via an index register mode, [mlrJ. Note that
register bank selection determines which accumulator is active.
Example
Add the constant 109 to the index register IW, (which is 16
bits wide).
SUBA A, A ;Clear the accumulator
ADD 109, R12 ;Add 109 to low byte of IW
ADCA R13, R13 ;Add carry to high byte of IW
Instruction Format
ADCA Rs, Rd
15 9
ADCA Rs, [mlr]
1
I
Rd
1 10 11 10 I 0 I 0 11 I I I I
_ Opcode .m.lr.
15 8 6 4
T-states
ADCA Rs, Rd
ADCA Rs, [mlrJ
Bus Timing
ADCA Rs, Rd
ADCA Rs, [mlrJ
Operation
ADCA Rs, Rd
00 - post-decrement
01 - no change
10 - post Increment
11 - pre-Increment
-2
-2
-Figure 7
-Figure 12
Rs + accumulator + carry bit -- Rd
ADCA
Rs, [mlrJ
Rs + accumulator + carry bit -- data memory
4
Rs
I I
Rs
00 •- IW
01 - IX
10 - IY
11 - IZ
o
°
TL/F/9336-5
ADD
Syntax
ADD n, rsd
Add Immediate
Affected Flags
N,Z,C,V
-immediate, limited register
Description
Adds the immediate value n to the register rsd and places
the result back into the register rsd. Note that only the active
registers RO-R15 may be specified for rsd. The value of
n is limited to 8 bits; (unsigned range: ° to 255, signed
range: + 127 to -128).
Example
Add the constant - 3 to register 10.
ADD -3, Rl0 ;Rl0 + (-3) -- Rl0
Instruction Format
1 °10101°1
. Opcode .
15 11
T-States
2
Bus Timing
Figure 7
Operation
rsd + n -- rsd
n
rsd
3 °
2-104