SN8F2280 Series
USB 2.0 Full-Speed 8-Bit Micro-Controller
8.4.3 TCnC COUNTING REGISTER
TCnC (n = 0, 1, 2) is an 8-bit counter register for TCn interval time control.
089H
TC0C
Read/Write
After reset
Bit 7
TC0C7
R/W
0
Bit 6
TC0C6
R/W
0
Bit 5
TC0C5
R/W
0
Bit 4
TC0C4
R/W
0
Bit 3
TC0C3
R/W
0
Bit 2
TC0C2
R/W
0
Bit 1
TC0C1
R/W
0
Bit 0
TC0C0
R/W
0
08CH
TC1C
Read/Write
After reset
Bit 7
TC1C7
R/W
0
Bit 6
TC1C6
R/W
0
Bit 5
TC1C5
R/W
0
Bit 4
TC1C4
R/W
0
Bit 3
TC1C3
R/W
0
Bit 2
TC1C2
R/W
0
Bit 1
TC1C1
R/W
0
Bit 0
TC1C0
R/W
0
08FH
TC2C
Read/Write
After reset
Bit 7
TC2C7
R/W
0
Bit 6
TC2C6
R/W
0
Bit 5
TC2C5
R/W
0
Bit 4
TC2C4
R/W
0
Bit 3
TC2C3
R/W
0
Bit 2
TC2C2
R/W
0
Bit 1
TC2C1
R/W
0
Bit 0
TC2C0
R/W
0
The equation of TCnC initial value is as following.
TCnC initial value = N - (TCn interrupt interval time * input clock)
N is TCn overflow boundary number. TCn timer overflow time has six types (TCn timer, TCn event counter, TCn Fcpu
clock source, TCn Fosc clock source, PWM mode and no PWM mode). These parameters decide TCn overflow time
and valid value as follow table.
TCnC valid
value
TCnC value
binary type
TCnCKS PWMn ALOADn TCnOUT
Remark
N
0
1
1
1
1
-
x
0
0
1
1
-
x
0
1
0
1
-
256
256
64
32
16
0x00~0xFF 00000000b~11111111b
0x00~0xFF 00000000b~11111111b
Overflow per 256 count
Overflow per 256 count
Overflow per 64 count
Overflow per 32 count
Overflow per 16 count
Overflow per 256 count
0
1
0x00~0x3F
0x00~0x1F
0x00~0x0F
xx000000b~xx111111b
xxx00000b~xxx11111b
xxxx0000b~xxxx1111b
256
0x00~0xFF 00000000b~11111111b
¾
Example: To set 1ms interval time for TCn interrupt. TCn clock source is Fcpu (TCnKS=0) and no PWM
output (PWMn=0). High clock is internal 6MHz. Fcpu=Fosc/2. Select TCnRATE=010 (Fcpu/64).
TCnC initial value = N - (TCn interrupt interval time * input clock)
= 256 - (1ms * 6MHz / 1 / 64)
= 256 - (10-3 * 6 * 106 / 1 / 64)
= 162
= A2H
The basic timer table interval time of TCn.
High speed mode (Fcpu = 6MHz / 1)
TCnRATE TCnCLOCK
Max overflow interval One step = max/256
000
001
010
011
100
101
110
111
Fcpu/256
Fcpu/128
Fcpu/64
Fcpu/32
Fcpu/16
Fcpu/8
10.923 ms
5.461 ms
2.731 ms
1.365 ms
0.683 ms
0.341 ms
0.171 ms
0.085 ms
42.67 us
21.33 us
10.67 us
5.33 us
2.67 us
1.33 us
0.67 us
0.33 us
Fcpu/4
Fcpu/2
SONiX TECHNOLOGY CO., LTD
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