tmp88cu74 TOSHIBA Semiconductor CORPORATION, tmp88cu74 Datasheet - Page 22

• Manufacturer Part Number: tmp88cu74
• Description: Cmos 8-bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

(3) SLOW mode
timer/counter 2 (TC2).
before performing the above operations. The timer/counter 2 (TC2) can conveniently be
used to confirm that low-frequency clock oscillation has stabilized.
a.
Note: The high frequency clock can be continued oscillation in order to return to
SLOW mode is controlled by the system control register 2 (SYSCR2) and the
When the low-frequency clock oscillation is unstable, wait until oscillation stabilizes
Switching from NORMAL2 mode to SLOW mode
low-frequency clock. Next, clear XEN (bit 7 in SYSCR2) to turn off high-frequency
oscillation.
Example 1: Switching from NORMAL2 mode to SLOW mode.
Example 2: Switching to the SLOW mode after low-frequency clock oscillation has stabilized.
PINTTC2:
VINTTC2:
First, set SYSCK (bit 5 in SYSCR2) to switch the main system clock to the
NORMAL2 mode from SLOW mode quickly.
Always turn off oscillation of high frequency clock when switching from SLOW
mode to STOP mode.
SET
CLR
LD
LDW
SET
LD
LD
SET
CLR
RETI
DL
(SYSCR2). 5
(SYSCR2). 7
(TC2CR), 14H
(TREG2), 8000H
(EIRH). EF14
(TC2CR), 34H
(TC2CR), 10H
(SYSCR2). 5
(SYSCR2). 7
PINTTC2
88CU74-22
;
;
;
;
;
;
;
;
;
SYSCK ← 1 (switches the main system
clock to the low-frequency clock)
XEN ← 0 (turns off high-frequency
oscillation)
Sets TC2 mode (timer mode, source
clock: fs)
Sets warming-up time (according to Xtal
characteristics)
Enables INTTC2
Starts TC2
Stops TC2
SYSCK ← 1 (switches the main system
clock to the low-frequency clock)
XEN ← 0 (turns off high-frequency
oscillation)
INTTC2 vector table
TMP88CU74
2007-10-19
2003-02-17