Chapter 9 XGATE (S12XGATEV2)
MC9S12XDP512 Data Sheet, Rev. 2.11
444 Freescale Semiconductor
Operation
RS.H - IMM8 - CNONE, only condition code flags get updated
Subtracts the carry bit and the 8-Bit constant IMM8 contained in the instruction code from the high byte
of the source register RD using binary subtraction and updates the condition code register accordingly. The
carry bit and Zero bits are taken into account to allow a 16-Bit compare in the form of
CMPL R2,#LOWBYTE
CPCH R2,#HIGHBYTE
BCC ; branch condition
Remark: There is no equivalent operation using triadic addressing. Comparing the values of two registers
can be performed by using the subtract instruction with R0 as destination register.
CCR Effects
Code and CPU Cycles
CPCH Compare Immediate 8-Bit Constant with
Carry (High Byte) CPCH
NZVC
∆∆∆∆
N: Set if bit 15 of the result is set; cleared otherwise.
Z: Set if the result is $00 and Z was set before this operation; cleared otherwise.
V: Set if a two´s complement overflow resulted from the operation; cleared otherwise.
RS[15] & IMM8[7] & result[15] | RS[15] & IMM8[7] & result[15]
C: Set if there is a carry from the bit 15 of the result; cleared otherwise.
RS[15] & IMM8[7] | RS[15] & result[15] | IMM8[7] & result[15]
Source Form Address
Mode Machine Code Cycles
CPCH RD, #IMM8 IMM8 1 1 0 1 1 RS IMM8 P