Renesas R8C/Tiny Series, Software Manual, Page: 134 / 297

117
3.2 Functions
Chapter 3 Functions
SHift Logical
Shift logical
[ Syntax ]
SHL.size src,dest
[ Related Instructions ] ROLC,RORC,ROT,SHA
SHL SHL
B , W , L
0
0
[ Operation ]
When
src
< 0
When
src
> 0
• This instruction logically shifts
dest
left or right the number of bits indicated by
src
. The bit overflowing
from LSB (MSB) is transferred to the C flag.
• The direction of shift is determined by the sign of
src
. If
src
is positive, bits are shifted left; if negative,
bits are shifted right.
• If
src
is an immediate, the number of shifts is –8 to –1 and +1 to +8. You cannot set values less than
–8, equal to 0, or greater than +8.
• If
src
is a register and you selected (.B) for the size specifier (.size), the number of shifts is –8 to +8.
Although you can set 0, no bits are shifted and no flags are changed. If you set a value less than –8 or
greater than +8, the result of shift is indeterminate.
• If
src
is a register and you selected (.W) or (.L) for the size specifier (.size), the number of shifts is –16
to +16. Although you can set 0, no bits are shifted and no flags are changed. If you set a value less
than –16 or greater than +16, the result of shift is indeterminate.
[ Function ]
[ Description Example ]
SHL.B #3,R0L ; Logically shifted left
SHL.B #–3,R0L ; Logically shifted right
SHL.L R1H,R2R0
src dest
R0L/R0 R0H/R1 R1L/R2 R1H
*1
/R3 R0L/R0 R0H/R1
*1
R1L/R2 R1H/R3
*1
A0/A0 A1/A1 [A0] [A1] A0/ A0 A1/ A1 [A0] [A1]
dsp:8[A0] dsp:8[A1] dsp:8[SB] dsp:8[FB] dsp:8[A0] dsp:8[A1] dsp:8[SB] dsp:8[FB]
dsp:16[A0] dsp:16[A1] dsp:16[SB] abs16 dsp:16[A0] dsp:16[A1] dsp:16[SB] abs16
dsp:20[A0] dsp:20[A1] abs20 #IMM
*2
dsp:20[A0] dsp:20[A1] abs20
R2R0 R3R1 A1A0 R2R0 *3 R3R1 *3 A1A0
[ Selectable src/dest ]
[ Flag Change ]
U I O B S Z D C
Conditions
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. However, the flag is
indeterminate if you selected (.L) for the size specifier (.size).
C : The flag is set when the bit shifted out last is 1; otherwise cleared. However, the flag is
indeterminate if you selected (.L) for the size specifier (.size).
[ Instruction Code/Number of Cycles ]
Page=228
MSB dest LSB
MSB dest LSB
C
C
Flag
Change
*1 If
src
is R1H, you cannot choose R1 or R1H for
dest
.
*2 The range of values that can be taken on is –8 < #IMM < +8. However, you cannot set 0.
*3 You can only specify (.L) for the size specifier (.size). For other
dest
, you can specify (.B) or (.W).
*1 If the number of shifts is 0, no flags are changed.