11 16-BIT TIMERS (T16)
S1C17M20/M21/M22/M23/M24/M25
Seiko Epson Corporation
11-1
TECHNICAL MANUAL (Rev. 1.0)
11 16-bit Timers (T16)
11.1 Overview
T16 is a 16-bit timer. The features of T16 are listed below.
• 16-bit presettable down counter
• Provides a reload data register for setting the preset value.
• A clock source and clock division ratio for generating the count clock are selectable.
• Repeat mode or one-shot mode is selectable.
• Can generate counter underflow interrupts.
Figure 11.1.1 shows the configuration of a T16 channel.
Table 11.1.1 T16 Channel Configuration of S1C17M20/M21/M22/M23/M24/M25
Item
S1C17M20/M23
S1C17M21/M24
S1C17M22/M25
24-pin package
32-pin package
Number of channels
4 channels (Ch.0–Ch.3)
Event counter function
Not supported (No EXCLm pins are provided.)
Peripheral clock output
(Outputs the counter underflow signal.)
Ch.1
→
Synchronous serial interface Ch.0 master clock
Ch.2
→
Synchronous serial interface Ch.1 master clock
Ch.3
→
12-bit A/D converter trigger signal
T16 Ch.n
To interrupt controller
(To peripheral circuit)
Underflow
PRESET
Timer control
circuit
Interrupt control
circuit
PRUN
TRMD
CLKSRC[1:0]
CLKDIV[3:0]
Clock generator
UFIE
UFIF
DBRUN
MODEN
CLK_T16_n
Timer counter
TC[15:0]
Reload register
TR[15:0]
Inter
nal data
bu
s
EXCLm
(
)
Figure 11.1.1 Configuration of a T16 Channel
11.2 Input Pin
Table 11.2.1 shows the T16 input pin.
Table 11.2.1 T16 Input Pin
Pin name
I/O
*
Initial status
*
Function
EXCLm
I
I (Hi-Z)
External event signal input pin
*
Indicates the status when the pin is configured for T16.
If the port is shared with the EXCL
m
pin and other functions, the EXCL
m
input function must be assigned to the
port before using the event counter function. For more information, refer to the “I/O Ports” chapter.