Chapter 6 XGATE (S12XGATEV2)
MC9S12XDP512 Data Sheet, Rev. 2.21
256
Freescale Semiconductor
Operation
n = RS or IMM4
Shifts the bits in register RD n positions to the right. The higher n bits of the register RD become lled
with the carry ag. The carry ag will be updated to the bit contained in RD[n-1] before the shift for n >0.
n can range from 0 to 16.
In immediate address mode, n is determined by the operand IMM4. n is considered to be 16 in IMM4 is
equal to 0.
In dyadic address mode, n is determined by the content of RS. n is considered to be 16 if the content of RS
is greater than 15.
CCR Effects
Code and CPU Cycles
CSR
Logical Shift Right with Carry
CSR
NZ
V
C
N:
Set if bit 15 of the result is set; cleared otherwise.
Z:
Set if the result is $0000; cleared otherwise.
V:
Set if a twos complement overow resulted from the operation; cleared otherwise.
RD[15]old ^ RD[15]new
C:
Set if n > 0 and RD[n-1] = 1; if n = 0 unaffected.
Source Form
Address
Mode
Machine Code
Cycles
CSR RD, #IMM4
IMM4
0
1
RD
IMM4
1
0
1
P
CSR RD, RS
DYA
0
1
RD
RS
1
0
1
P
C
RD
C
n bits
C
n