SN8P1700
8-bit micro-controller build-in 12-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 127
Revision 1.93
TC1C COUNTING REGISTER
TC1C is an 8-bit counter register for the timer counter (TC1). TC1C must be reset whenever the TC1ENB is set “1” to
start the timer. TC0C is incremented by one with a clock pulse which the frequency is determined by TC0RATE0 ~
TC0RATE2. When TC0C has incremented to “0FFH”, it is will be cleared to “00H” in next clock and an overflow is
generated. Under TC1 interrupt service request (TC1IEN) enable condition, the TC1 interrupt request flag will be set
“1” and the system executes the interrupt service routine.
TC1C initial value = xxxx xxxx
0DDH
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
TC1C
TC1C7 TC1C6 TC1C5 TC1C4 TC1C3 TC1C2 TC1C1 TC1C0
R/W R/W R/W R/W R/W R/W R/W R/W
The interval time of TC1 basic timer table.
High speed mode (fcpu = 3.58MHz / 4)
Low speed mode (fcpu = 32768Hz / 4)
TC1RATE
TC1CLOC
K
Max overflow interval
One step = max/256
Max overflow interval
One step = max/256
000
fcpu/256
73.2 ms
286us
8000 ms
31.25 ms
001
fcpu/128
36.6 ms
143us
4000 ms
15.63 ms
010
fcpu/64
18.3 ms
71.5us
2000 ms
7.8 ms
011
fcpu/32
9.15 ms
35.8us
1000 ms
3.9 ms
100
fcpu/16
4.57 ms
17.9us
500 ms
1.95 ms
101
fcpu/8
2.28 ms
8.94us
250 ms
0.98 ms
110
fcpu/4
1.14 ms
4.47us
125 ms
0.49 ms
111
fcpu/2
0.57 ms
2.23us
62.5 ms
0.24 ms
Table 7-4. The Timing Table of Timer Count TC1
The equation of TC1C initial value is as following.
TC1C initial value = 256 - (TC1 interrupt interval time * input clock)
Example: To set 10ms interval time for TC1 interrupt at 3.58MHz high-speed mode. TC1C value (74H) = 256 -
(10ms * fcpu/64)
TC1C initial value = 256 - (TC1 interrupt interval time * input clock)
= 256 - (10ms * 3.58 * 10
6
/ 4 / 64)
= 256 - (10
-2
* 3.58 * 10
6
/ 4 / 64)
= 116
= 74H