Renesas R8C/Tiny Series Software Manual page 79

Chapter 3 Functions
CMP
[ Syntax ]
CMP.size (:format) src,dest
[ Operation ]
dest – src
[ Function ]
• Each flag bit of the flag register varies depending on the result of subtraction of
dest
• If is an A0 or A1 when the size specifier (.size) you selected is (.B),
perform operation in 16 bits. If
or A1.
[ Selectable src/dest ]
R0L/R0 R0H/R1
A0/A0 *1 A1/A1 *1
dsp:8[A0] dsp:8[A1]
dsp:16[A0] dsp:16[A1]
dsp:20[A0] dsp:20[A1]
R2R0 R3R1
*1 If you specify (.B) for the size specifier (.size), you cannot choose A0 or A1 for
neously.
[ Flag Change ]
U I O B
Flag
Change
Conditions
O : The flag is set when a signed operation resulted in exceeding +32767 (.W) or –32768 (.W), or
+127 (.B) or –128 (.B); otherwise cleared.
S : The flag is set when the operation resulted in MSB = 1; otherwise cleared.
Z : The flag is set when the operation resulted in 0; otherwise cleared.
C : The flag is set when an unsigned operation resulted in any value equal to or greater than 0;
otherwise cleared.
[ Description Example ]
CMP.B:S #10,R0L
CMP.W:G R0,A0
CMP.W #–3,R0
CMP.B #5,Ram:8[FB]
CMP.B A0,R0L
G , Q , S (Can be specified)
B , W
src
is an A0 or A1, operation is performed on the 8 low-order bits of A0
(See the next page for
src
R1L/R2 R1H/R3
[A0] [A1]
dsp:8[SB] dsp:8[FB] dsp:8[A0]
dsp:16[SB] abs16
abs20 #IMM
A1A0
S Z D C
Compare
CoMPare
[ Instruction Code/Number of Cycles ]
R0L/R0 R0H/R1
A0/A0 *1 A1/A1
dsp:8[A1]
dsp:16[A0] dsp:16[A1] dsp:16[SB] abs16
dsp:20[A0] dsp:20[A1] abs20
R2R0 R3R1
; A0's 8 low-order bits and R0L are compared.
62
3.2 Functions
src
from
src
is zero-expanded to
src dest
/ classified by format.)
dest
R1L/R2 R1H/R3
*1 [A0] [A1]
dsp:8[SB] dsp:8[FB]
SP/SP
A1A0
src dest
and
CMP
Page=161
dest
.
simulta-