Toshiba TLCS-900 Computer Hardware User Manual


 
TMP92CM22
2007-02-16
92CM22-25
(3) Operation
a. IDLE2 mode
In IDLE2 mode only specific internal I/O operations, as designated by the
IDLE2 setting register, can take place. Instruction execution by the CPU stops.
Figure 3.3.6 illustrates an example of the timing for clearance of the IDLE2
mode halt state by an interrupt.
Interrupt o
f
releasing halt
IDLE2
mode
Data
Data
X1
A0 to A23
D0 to D15
RD
WR
Figure 3.3.6 Timing Chart for IDLE2 Mode Halt State Released by Interrupt
b. IDLE1 mode
In IDLE1 mode, only the internal oscillator operates. The system clock stops.
And, pin state in IDLE1 mode depend on setting SYSCR2<SELDRV, DRVE>
register.
Table 3.3.5, Table 3.3.6 shows pin state in IDLE1 mode.
In the halt state, the interrupt request is sampled asynchronously with the
system clock; however, clearance of the halt state (e.g., restart of operation) is
synchronous with it.
Figure 3.3.7 shows the timing for release of the IDLE1 mode halt state by an
interrupt.
IDLE1
mode
Data
Data
X1
A0 to A23
D0 to D15
RD
WR
Interrupt o
f
releasing halt
Figure 3.3.7 Timing Chart for IDLE1 Mode Halt State Released by Interrupt