Table of Contents
Advertisement
7 DETAILS OF INSTRUCTIONS
cmc
%rd, %rs
cmc/c
%rd, %rs
cmc/nc %rd, %rs
Function
16-bit comparison with carry
Standard)
Extension 1) rs(15:0) - imm13(zero extended) - C
Extension 2) rs(15:0) - imm16 - C
15 14 13 12 11 10
Code
0
0
1
|
|
0
0
1
|
|
0
0
1
|
|
IL
IE
C
Flag
|
|
– ↔ ↔ ↔ ↔
–
|
|
– ↔ ↔ ↔
–
–
Mode
Src: Register direct %rs = %r0 to %r7
Dst: Register direct %rd = %r0 to %r7
CLK
One cycle
Description
(1) Standard
cmc
Subtracts the contents of the rs register and C (carry) flag from the contents of the rd register,
and sets or resets the flags (C, V, Z and N) according to the results. The operation is performed
in 16-bit size. It does not change the contents of the rd register.
(2) Extension 1
ext
cmc
Subtracts the contents of the 13-bit immediate imm13 and C (carry) flag from the contents of
the rs register, and sets or resets the flags (C, V, Z and N) according to the results. The imm13
is zero-extended into 16 bits prior to the operation. The operation is performed in 16-bit size. It
does not change the contents of the rd and rs registers.
* This combination does not use the rd register value for comparison.
(3) Extension 2
ext
ext
cmc
Subtracts the contents of the 16-bit immediate imm16 and C (carry) flag from the contents of
the rs register, and sets or resets the flags (C, V, Z and N) according to the results. The operation
is performed in 16-bit size. It does not change the contents of the rd and rs registers.
* This combination does not use the rd register value for comparison.
(4) Conditional execution
The /c or /nc suffix on the opcode specifies conditional execution.
cmc/c
cmc/nc Executed as cmc when the C flag is 0 or executed as nop when the flag is 1
In this case, the ext instruction can be used to extend the operand.
The conditional execution instruction above sets/resets the flags (V, Z and N) according to the
results if it is executed.
7-18
rd(15:0) - rs(15:0) - C
9
8
7
6
|
|
1
1
1
r d
1
|
|
|
|
|
|
|
1
1
1
r d
0
|
|
|
|
|
|
|
1
1
1
0
r d
|
|
|
|
|
V
Z
N
|
|
|
cmc
|
|
|
cmc/c, cmc/nc
%rd,%rs
; rd - rs - C
imm13
%rd,%rs
; rs - imm13 - C
imm3
; imm3(2:0) = imm16(15:13)
imm13
; = imm16(12:0)
%rd,%rs
; rs - imm16 - C
Executed as cmc when the C flag is 1 or executed as nop when the flag is 0
Seiko Epson Corporation
5
4
3
2
1
0
|
0
0
1
r s
|
|
|
|
|
|
0
0
1
r s
|
|
|
|
|
|
1
0
1
r s
|
|
|
|
|
cmc
cmc/c
cmc/nc
S1C17 CORE MANUAL
(REV. 1.2)
Advertisement
Table of Contents
