16 SEVEN-SEGMENT LED CONTROLLER (LEDC)
16-2
Seiko Epson Corporation
S1C17M12/M13 TECHNICAL MANUAL
(Rev. 1.2)
16.2 Output Pins and External Connections
16.2.1 List of Output Pins
Table 16.2.1.1 lists the LEDC pins.
Table 16.2.1.1 List of LEDC Pins
Pin name
I/O
*
1
Initial status
*
1
Function
COM0–7
O
O (L)
Common output pins
SEG0–7
O
Hi-Z
Segment output pins
*
1: Indicates the status when the pin is configured for LEDC.
If the port is shared with the LEDC pin and other functions, the LEDC output function must be assigned to the port
before activating the LEDC. For more information, refer to the “I/O Ports” chapter.
16.2.2 External Connections
Figure 16.2.2.1 shows a connection diagram between LEDC and seven-segment LED modules.
SEG0
SEG1
SEG2
SEG3
SEG4
SEG5
SEG6
SEG7
COM0
COM1
COM
x
R
COM
COM
COM
a
b
c
d
e
f
g
dp
S1C17 LEDC
a
g
d
dp
b
f
c
e
Figure 16.2.2.1 Connections between LEDC and Seven-Segment LED Modules
The resistance value of R (current limiting resistor) should be determined after being evaluated using the actual tar-
get system.
16.3 Clock Settings
16.3.1 LEDC Operating Clock
When using LEDC, the LEDC operating clock CLK_LEDC must be supplied to the LEDC from the clock
generator. The CLK_LEDC supply should be controlled as in the procedure shown below.
1. Enable the clock source in the clock generator if it is stopped (refer to “Clock Generator” in the “Power Supply,
Reset, and Clocks” chapter).
2. Set the following LEDCCLK register bits:
- LEDCCLK.CLKSRC[1:0] bits
(Clock source selection)
- LEDCCLK.CLKDIV[2:0] bits
(Clock division ratio selection = Clock frequency
16.3.2 Clock Supply in SLEEP Mode
When using LEDC during SLEEP mode, the LEDC operating clock CLK_LEDC must be configured so that it will
keep supplying by writing 0 to the CLGOSC.
xxxx
SLPC bit for the CLK_LEDC clock source.