14 8-BIT TIMERS (T8)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
14-5
8.1 Delay Patterns Specified by TFMD[3:0]
Table 14.
TFMD[3:0]
Underflow number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
0x0
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
0x1
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
D
0x2
–
–
–
–
–
–
–
D
–
–
–
–
–
–
–
D
0x3
–
–
–
–
–
–
–
D
–
–
–
D
–
–
–
D
0x4
–
–
–
D
–
–
–
D
–
–
–
D
–
–
–
D
0x5
–
–
–
D
–
–
–
D
–
–
–
D
–
D
–
D
0x6
–
–
–
D
–
D
–
D
–
–
–
D
–
D
–
D
0x7
–
–
–
D
–
D
–
D
–
D
–
D
–
D
–
D
0x8
–
D
–
D
–
D
–
D
–
D
–
D
–
D
–
D
0x9
–
D
–
D
–
D
–
D
–
D
–
D
–
D
D
D
0xa
–
D
–
D
–
D
D
D
–
D
–
D
–
D
D
D
0xb
–
D
–
D
–
D
D
D
–
D
D
D
–
D
D
D
0xc
–
D
D
D
–
D
D
D
–
D
D
D
–
D
D
D
0xd
–
D
D
D
–
D
D
D
–
D
D
D
D
D
D
D
0xe
–
D
D
D
D
D
D
D
–
D
D
D
D
D
D
D
0xf
–
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D: Indicates the insertion of a delay cycle.
Count clock
Underflow signal (not corrected)
Underflow signal (corrected)
Output clock (not corrected)
Output clock (corrected)
Delayed
15
16
15
16
1
1
8.1 Delay Cycle Insertion in Fine Mode
Figure 14.
At initial reset, TFMD[3:0] is set to 0x0, preventing insertion of delay cycles.
T8 Interrupts
14.9
T8 outputs an interrupt request to the interrupt controller (ITC) when the counter underflows.
Timer underflow interrupt
When the counter underflows, the interrupt flag T8IF/T8_INT
x
register, which is provided for each channel in
the T8 module, is set to 1. At the same time, an interrupt request is sent to the ITC if T8IE/T8_INT
x
register has
been set to 1 (interrupt enabled). An interrupt is generated if the ITC and C33 PE Core interrupt conditions are
satisfied.
If T8IE is set to 0 (interrupt disabled, default), no interrupt request will be sent to the ITC.
For specific information on interrupt processing, see the “Interrupt Controller (ITC)” chapter.
Notes: • The T8 module interrupt flag T8IF must be reset in the interrupt handler routine after a T8 in-
terrupt has occurred to prevent recurring interrupts.
• Reset T8IF before enabling T8 interrupts with T8IE to prevent occurrence of unwanted inter-
rupt. T8IF is reset by writing 1.