mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 228

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

BFFO
Chapter 6 XGATE (S12XGATEV2)
Operation
FirstOne (RS)
Searches the first “1” in register RS (from MSB to LSB) and writes the bit position into the destination
register RD. The upper bits of RD are cleared. In case the content of RS is equal to $0000, RD will be
cleared and the carry flag will be set. This is used to distinguish a “1” in position 0 versus no “1” in the
whole RS register at all.
CCR Effects
1
Code and CPU Cycles
228
N:
Z:
V:
C:
BFFO RD, RS
0
N
Before executing the instruction
0; cleared.
Set if the result is $0000; cleared otherwise.
0; cleared.
Set if RS = $0000
Z
0
V
Source Form
C
RD;
1
; cleared otherwise.
Address
MC9S12XDP512 Data Sheet, Rev. 2.17
Mode
DYA
Bit Field Find First One
0
0
0
0
1
Machine Code
RD
RS
1
0
Freescale Semiconductor
BFFO
0
0
0
Cycles
P