CHAPTER 9 CLOCK GENERATION FUNCTION
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User’s Manual U14359EJ4V0UM
(3) Power-save control register (PSC)
This is an 8-bit register that controls the power-save function. This register, which is one of the specific
registers, is valid only when accessed in a specific sequence during a write operation.
This register can be read or written in 8-bit or 1-bit units. If bit 7 or 6 is set to 1, operation cannot be
guaranteed.
Caution
It is impossible to set the STB bit and the NMIM or INTM bit at the same time. Be sure to set
the STB bit after setting the NMIM or INTM bit.
7
6
<5>
<4>
3
2
<1>
0
Address
After reset
PSC
0
0
NMIM
INTM
0
0
STB
0
FFFFF1FEH
00H
Bit position
Bit name
Function
5
NMIM
NMI Mode
This is the enable/disable setting bit for standby mode release using the valid edge
input of NMI.
0: Release by NMI enabled
1: Release by NMI disabled
4
INTM
INT Mode
This is the enable/disable setting for standby mode release using an unmasked
maskable interrupt (INTP1nn) (n = 0 to 3).
0: Release by maskable interrupt enabled
1: Release by maskable interrupt disabled
1
STB
Standby Mode
Indicates the standby mode status.
If 1 is written to this bit, the system enters IDLE or software STOP mode (set by the
PSM bit of the PSMR register). When standby mode is released, this bit is
automatically reset to 0.
0: Standby mode is released
1: Standby mode is in effect
Set data in the power-save control register (PSC) in the following sequence.
<1> Set the power-save mode register (PSMR) (with the following instructions).
•
Store instruction (ST/SST instruction)
•
Bit manipulation instruction (SET1/CLR1/NOT1 instruction)
<2> Prepare data in any one of the general-purpose registers to set to the specific register.
<3> Write data to the command register (PRCMD).
<4> Set the power-save control register (PSC) (with the following instructions).
•
Store instruction (ST/SST instruction)
•
Bit manipulation instruction (SET1/CLR1/NOT1 instruction)
<5> Assert the NOP instructions (5 instructions (<5> to <9>).