upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 152

• Manufacturer Part Number: upd70f3017ay
• Description: V850/sa1tm 32-/16-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

(2) While an instruction is being executed on external ROM
152
(i) Do not set the power save mode (IDLE or software STOP mode) while an instruction is being executed on
(ii) To set the power save mode (IDLE or software STOP mode) while an instruction is being executed on the
the external ROM.
external ROM, handle as follows.
<1> Insert six NOP instructions 4 bytes after the instruction that writes to the PSC register.
<2> Insert the BR $+2 instruction following the NOP instruction to eliminate the discrepancy of the program
[Processing program example]
LDSR rX.5
ST.B r0, PRCMD[r0]
ST.B rD, RSC[r0]
LDSR rY, 5
NOP
NOP
NOP
NOP
NOP
NOP
BR
rX: Value to be written to PSW
rY: Value to be rewritten to PSW
rD: Value to be set to PSC
counter (PC).
$+2
CHAPTER 6 CLOCK GENERATION FUNCTION
; NP bit = 1
; Write to PRCMD
; PSC register setting
; NP bit = 0
; NOP instruction (6 instructions)
; Eliminate discrepancy of PC
User’s Manual U12768EJ4V1UD