tmp89fm82 TOSHIBA Semiconductor CORPORATION, tmp89fm82 Datasheet - Page 56

• Manufacturer Part Number: tmp89fm82
• Description: 8 Bit Microcontroller Tlcs-870/c1 Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

2.3
System clock controller
RA000
PINTWUC:
VINTWUC:
Example 1: Switching from the NORMAL2 mode to the SLOW1 mode (when fc is used as the basic clock for the high-
Example 2: When it is operated in the high frequency clock, switching to the SLOW1 mode after the stable oscillation of the
(2)
up counter that the oscillation of the basic clock for the high-frequency clock has stabilized, and then
clear SYSCR2<SYSCK> to "0".
main system clock (fm) is switched to fcgck.
off the low-frequency clock oscillator.
Set SYSCR2<XEN> to "1" to enable the high-frequency clock (fc) to oscillate. Confirm at the warm-
When a maximum of 8/fs + 2.5/fcgck [s] has elapsed since SYSCR2<SYSCK> is cleared to "0", the
After switching, wait for 2 machine cycles or longer, and then clear SYSCR2<XTEN> to "0" to turn
Switching from the SLOW1 mode to the NORMAL1 mode
SET
NOP
NOP
CLR
; #### Initialize routine ####
SET
¦
¦
LD
LD
SET
SET
¦
; #### Interrupt service routine of warm-up counter interrupts ####
SET
NOP
NOP
CLR
RETI
¦
DW
frequency clock)
low-frequency clock oscillation circuit is confirmed at the warm-up counter (fs=32.768kHz, warm-up time = about
100 ms)
(SYSCR2).4
(SYSCR2).6
(P0FC).2
(WUCCR), 0x02
(WUCDR), 0x33
(EIRL).4
(SYSCR2).5
(SYSCR2).4
(SYSCR2).6
PINTWUC
Page 40
;SYSCR2<SYSCK> = 1
;(Switches the main system clock to the basic clock for the
;low-frequency clock for the SLOW2 mode)
;Waits for 2 machine cycles
;SYSCR2<XEN> = 0
;(Turns off the high-frequency clock oscillation circuit)
;P0FC2 = 1 (Uses P02/03 as oscillators)
;WUCCR<WUCDIV> = 00 (No division)
;WUCCR<WUCSEL> = 1 (Selects fs as the source clock)
;Sets the warm-up time
;(Determines the time depending on the oscillator characteristics)
;100 ms/1.95 ms = 51.2 → round up to 0x33
;Enables INTWUC interrupts
;SYSCR2<XTEN> = 1
;(Starts the low-frequency clock oscillation and starts the warm-up
;counter)
;SYSCR2<SYSCK> = 1
;(Switches the main system clock to the low-frequency clock)
;Waits for 2 machine cycles
;SYSCR2<XEN> = 0
;(Turns off the high-frequency clock oscillation circuit)
;INTWUC vector table
TMP89FM82