Specifications

EPSON 10–13
SED1280
SED1280
Key Scanning
An 8 × 10-key matrix can be scanned using SWS1 to
SWS8 scan outputs and SWC1 to SWC10 scan inputs.
The SWS1 timing during one scan interval and SWS1 to
SWS8 timing during several scans are shown in the
following figures.
SWS1
SWS1
SWS2
SWS3
SWS8
5 ms 5 ms
5ms
80 µs
LED control period
Key
scan
period
40 ms
.
.
.
.
.
.
Key scan initialization
A key scan starts automatically once the first block of
data is received from the host, after a reset. The 5 ms scan
cycle runs continuously, once started, as shown in the
following figure.
Expanded Input Ports
Scanning of the EO1 to EO3 expanded input ports starts
automatically once the first block of data is received from
the host, after a reset.
LED Controller
Up to 40 LEDs can be connected to SWS1 to SWS8 and
LE1 to LE5 to form an 8 × 5 matrix.
To control the LEDs, LE1 to LE5 are connected to the
based of external pnp transistors, and SWS1 to SWS8, to
the LED anodes.
RST
SID
SWS1
Key scan period LED control period