SM8521 Datasheet, PDF (31/56 Pages) Sharp Electrionic Components – 8-Bit Single-Chip Microcomputer

8-BIT TIMER REGISTER
TM0C, TM1C (Control registers)
Bit 7
0
TMXC7 TMXC6 TMXC5 TMXC4 TMXC3 TMXC2 TMXC1 TMXC0
(x = 0, 1)
Bit 7 : Start/stop
Bits 6 to 3 : Set ‘0’
Bits 2 to 0 :
PRESCALER INPUT CLOCK FOR 8-BIT UP-COUNTER
000 fCK/2
001 fCK/1 024
010 fCK/2 048
011 fCK/4 096
100 fCK/8 192
101 fCK/16 384
110 fCK/32 768
111 fCK/65 536
32.768 kHz
1s
Prescaler
SM8521
TM0D, TM1D (Data register)
Bit 7
0
TMXD7 TMXD6 TMXD5 TMXD4 TMXD3 TMXD2 TMXD1 TMXD0
(x = 0, 1)
Bits 7 to 0 : Content of counter (read), time con-
stant (write)
NOTES :
• After reset, the status of both TM0C and TM1C becomes
0∗∗∗∗000B, and both TM0D and TM1D becomes
00000000B.
• Every time between the value of 8-bit up counter and the
value of time constant register coincide in timer execution,
output signal inverts.
Clock Timer
Clock timer is for real time clock. Dividing sub-clock
(32.768 kHz), 1 s or 1 min interrupt occurs.
1/60 counter
1 min
Selector
Interrupt
Control register
Data bus
NOTE : In case of run/reset bit is zero, both upper 8 bits in prescaler and all bits in 1/60 counter are reset.
Fig. 14 Clock Timer Block Diagram
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