Datasheet

Section 2 CPU
Rev. 2.00 Jul. 04, 2007 Page 44 of 692
REJ09B0309-0200
3. Finally, the CPU writes H'41 to PDR5, completing execution of BSET instruction.
As a result of the BSET instruction, bit 0 in PDR5 becomes 1, and P50 outputs a high-level
signal. However, bits 7 and 6 of PDR5 end up with different values. To prevent this problem,
store a copy of the PDR5 data in a work area in memory. Perform the bit manipulation on the
data in the work area, then write this data to PDR5.
• Prior to executing BSET instruction
MOV.B H'80, R0L
MOV.B R0L, @RAM0
MOV.B R0L, @PDR5
The PDR5 value (H'80) is written to a work area in
memory (RAM0) as well as to PDR5.
P57 P56 P55 P54 P53 P52 P51 P50
Input/output Input Input Output Output Output Output Output Output
Pin state Low
level
High
level
Low
level
Low
level
Low
level
Low
level
Low
level
Low
level
PCR5 0 0 1 1 1 1 1 1
PDR5 1 0 0 0 0 0 0 0
RAM0 1 0 0 0 0 0 0 0
• BSET instruction executed
BSET #0, @RAM0:8
The BSET instruction is executed designating the PDR5
work area (RAM0).
• After executing BSET instruction
MOV.B @RAM0, R0L
MOV.B R0L, @PDR5
The work area (RAM0) value is written to PDR5.
P57 P56 P55 P54 P53 P52 P51 P50
Input/output Input Input Output Output Output Output Output Output
Pin state Low
level
High
level
Low
level
Low
level
Low
level
Low
level
Low
level
High
level
PCR5 0 0 1 1 1 1 1 1
PDR5 1 0 0 0 0 0 0 1
RAM0 1 0 0 0 0 0 0 1