Function - Toshiba TLCS-870/C Series Manual

7. Time Base Timer (TBT)
7.1 Time Base Timer
Note 2: The interrupt frequency (TBTCK) must be selected with the time base timer disabled (TBTEN="0"). (The interrupt fre-
quency must not be changed with the disable from the enable state.) Both frequency selection and enabling can be per-
formed simultaneously.
Example :Set the time base timer frequency to fc/2
Table 7-1 Time Base Timer Interrupt Frequency ( Example : fc = 16.0 MHz, fs = 32.768 kHz )

7.1.3 Function

An INTTBT ( Time Base Timer Interrupt ) is generated on the first falling edge of source clock ( The divider
output of the timing generator which is selected by TBTCK. ) after time base timer has been enabled.
The divider is not cleared by the program; therefore, only the first interrupt may be generated ahead of the set
interrupt period ( Figure 7-2 ).
LD (TBTCR) , 00000010B
LD (TBTCR) , 00001010B
DI
SET (EIRL) . 6
TBTCK
NORMAL1/2, IDLE1/2 Mode
DV7CK = 0
000 1.91
001 7.63
010 244.14
011 976.56
100 1953.13
101 3906.25
110 7812.5
111 31250
Source clock
TBTCR<TBTEN>
INTTBT
Enable TBT
Figure 7-2 Time Base Timer Interrupt
16
[Hz] and enable an INTTBT interrupt.
; TBTCK ← 010
; TBTEN ← 1
; IMF ← 0
Time Base Timer Interrupt Frequency [Hz]
NORMAL1/2, IDLE1/2 Mode
DV7CK = 1
1
4
128
512
1024
2048
4096
16384
Interrupt period
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TMP86PM29BUG
SLOW1/2, SLEEP1/2 Mode
1
4
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