14 8-BIT TIMERS (T8)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
14-7
Address
Register name
Function
0x301174
T8_TC7
T8 Ch.7 Counter Data Register
Counter data
0x301176
T8_CTL7
T8 Ch.7 Control Register
Set timer mode and start/stop timer
0x301178
T8_INT7
T8 Ch.7 Interrupt Control Register
Control interrupt
The 8-bit timer registers are described in detail below. These are 16-bit registers.
Note: When data is written to the registers, the “Reserved” bits must always be written as 0 and not 1.
T8 Ch.
x
Input Clock Select Registers (T8_CLK
x
)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
T8 Ch.
x
Input
Clock Select
Register
(T8_CLK
x
)
0x301100
|
0x301170
(16 bits)
D15–4 –
reserved
–
–
–
0 when being read.
D3–0 DF[3:0]
T8 clock division ratio select
(Prescaler output clock)
DF[3:0]
Division ratio
0x0 R/W Source clock =
PCLK1 (Ch.0/2/4/6)
or
PCLK2 (Ch.1/3/5/7)
0xf
0xe
0xd
0xc
0xb
0xa
0x9
0x8
0x7
0x6
0x5
0x4
0x3
0x2
0x1
0x0
reserved
1/16384
1/8192
1/4096
1/2048
1/1024
1/512
1/256
1/128
1/64
1/32
1/16
1/8
1/4
1/2
1/1
D[15:4] Reserved
D[3:0]
DF[3:0]: T8 Input Clock Division Ratio Select Bits
Selects a PCLK division ratio to generate the T8 count clock.
10.2 Count Clock (PCLK Division Ratio) Selection
Table 14.
DF[3:0]
Division ratio
DF[3:0]
Division ratio
0xf
Reserved
0x7
1/128
0xe
1/16384
0x6
1/64
0xd
1/8192
0x5
1/32
0xc
1/4096
0x4
1/16
0xb
1/2048
0x3
1/8
0xa
1/1024
0x2
1/4
0x9
1/512
0x1
1/2
0x8
1/256
0x0
1/1
*
Source clock = PCLK1 (for T8 Ch.0/2/4/6) or PCLK2 (for T8 Ch.1/3/5/7)
(Default: 0x0)
Note: Make sure the counter is halted before setting the count clock.
T8 Ch.
x
Reload Data Registers (T8_TR
x
)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
T8 Ch.
x
Reload
Data Register
(T8_TR
x
)
0x301102
|
0x301172
(16 bits)
D15-8 –
reserved
–
–
–
0 when being read.
D7–0 TR[7:0]
T8 reload data
TR7 = MSB
TR0 = LSB
0x0 to 0xff
0x0 R/W
D[15:8] Reserved
D[7:0]
TR[7:0]: T8 Reload Data Bits
Sets the counter initial value. (Default: 0x0)
The reload data set in this register is preset to the counter when the timer is reset or the counter under-
flows. If the timer is started after resetting, it counts down from the reload value (initial value). This
means that the reload value and the input clock frequency determine the time elapsed from the point at
which the timer starts until the underflow occurs (or between underflows). The time determined is used
to obtain the desired wait time, the intervals between periodic interrupts or A/D triggers, and the pro-
grammable serial interface transfer clock.