CHAPTER 4 BUS CONTROL FUNCTION
129
User’s Manual U14492EJ3V0UD
4.8.3 Operation in power save mode
In the software STOP or IDLE mode, the internal system clock is stopped. Consequently, the bus hold state is not
accepted and set since the HLDRQ pin cannot be accepted even if it becomes active.
In the HALT mode, the HLDAK pin immediately becomes active when the HLDRQ pin becomes active, and the bus
hold state is set. When the HLDRQ pin becomes inactive after that, the HLDAK pin also becomes inactive. As a
result, the bus hold state is cleared and the HALT mode is set again.
4.8.4
Bus hold timing
T2
T3
TH
TH
TH
TH
TI
T1
CLKOUT (output)
HLDRQ (input)
HLDAK (output)
A16 to A23 (output)
AD0 to AD15 (I/O)
ASTB (output)
RD (output)
LWR, UWR (output)
CSn (output)
WAIT (input)
Address
Address
Undefined
Data
Address
Address
Undefined
Remarks 1.
The circles indicate the sampling timing.
2.
The broken lines indicate the high-impedance state.
3.
n = 0 to 7
Содержание V850E/IA1 mPD703116
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