tmp86fh09amg TOSHIBA Semiconductor CORPORATION, tmp86fh09amg Datasheet - Page 36

• Manufacturer Part Number: tmp86fh09amg
• Description: 8 Bit Microcontroller Tlcs-870/c Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

2.2
System Clock Controller
Example 1 :Switching from NORMAL2 mode to SLOW1 mode.
Example 2 :Switching to the SLOW1 mode after low-frequency clock has stabilized.
PINTTC4:
VINTTC4:
(1)
The following is the methods to switch the mode with the warm-up counter.
SLOW2 mode. Next, clear SYSCR2<XEN> to turn off high-frequency oscillation.
forming the above operations. The timer/counter (TC4,TC3) can conveniently be used to confirm
that low-frequency clock oscillation has stabilized.
First, set SYSCR2<SYSCK> to switch the main system clock to the low-frequency clock for
Note:The high-frequency clock can be continued oscillation in order to return to NORMAL2 mode
Switching from NORMAL2 mode to SLOW1 mode
When the low-frequency clock oscillation is unstable, wait until oscillation stabilizes before per-
SET
CLR
SET
LD
LD
LDW
DI
SET
EI
SET
:
CLR
SET
CLR
RETI
:
DW
from SLOW mode quickly. Always turn off oscillation of high-frequency clock when switching
from SLOW mode to stop mode.
(SYSCR2). 5
(SYSCR2). 7
(SYSCR2). 6
(TC3CR), 43H
(TC4CR), 05H
(TTREG3), 8000H
(EIRH). 3
(TC4CR). 3
(TC4CR). 3
(SYSCR2). 5
(SYSCR2). 7
PINTTC4
Page 26
; SYSCR2<SYSCK> ← 1
; (Switches the main system clock to the low-frequency clock for SLOW2)
; SYSCR2<XEN> ← 0
; (Turns off high-frequency oscillation)
; SYSCR2<XTEN> ← 1
; Sets mode for TC4, 3 (16-bit mode, fs for source)
; Sets warming-up counter mode
; Sets warm-up time (Depend on oscillator accompanied)
; IMF ← 0
; Enables INTTC4
; IMF ← 1
; Starts TC4, 3
; Stops TC4, 3
; SYSCR2<SYSCK> ← 1
; (Switches the main system clock to the low-frequency clock)
; SYSCR2<XEN> ← 0
; (Turns off high-frequency oscillation)
; INTTC4 vector table
TMP86FH09AMG