TMP86PM29BUG Datasheet, PDF (43/204 Pages) Toshiba Semiconductor – 8 Bit Microcontroller

TMP86PM29BUG
(2) Switching from SLOW1 mode to NORMAL2 mode
First, set SYSCR2<XEN> to turn on the high-frequency oscillation. When time for stabilization
(Warm up) has been taken by the timer/counter (TC4,TC3), clear SYSCR2<SYSCK> to switch the
main system clock to the high-frequency clock.
SLOW mode can also be released by inputting low level on the RESET pin. After releasing reset, the
operation mode is started from NORMAL1 mode.
Note: After SYSCK is cleared to “0”, executing the instructions is continiued by the low-frequency clock
for the period synchronized with low-frequency and high-frequency clocks.
High-frequency clock
Low-frequency clock
Main system clock
SYSCK
Example :Switching from the SLOW1 mode to the NORMAL2 mode (fc = 16 MHz, warm-up time is 4.0 ms).
SET
(SYSCR2). 7
; SYSCR2<XEN> ← 1 (Starts high-frequency oscillation)
LD
(TC3CR), 63H
; Sets mode for TC4, 3 (16-bit mode, fc for source)
LD
(TC4CR), 05H
; Sets warming-up counter mode
LD
(TTREG4), 0F8H
; Sets warm-up time
DI
; IMF ← 0
SET
(EIRH). 3
EI
; Enables INTTC4
; IMF ← 1
SET
(TC4CR). 3
; Starts TC4, 3
:
PINTTC4:
CLR
CLR
(TC4CR). 3
(SYSCR2). 5
; Stops TC4, 3
; SYSCR2<SYSCK> ← 0
(Switches the main system clock to the high-frequency clock)
RETI
:
VINTTC4:
DW
PINTTC4
; INTTC4 vector table
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