S6A0073 Datasheet, PDF (50/78 Pages) Samsung semiconductor – 34COM/60SEG DRIVER & CONTROLLER FOR DOT MATRIX LCD

S6A0073
34COM/60SEG DRIVER & CONTROLLER FOR DOT MATRIX LCD
Interface with MPU in Serial Mode
When IM input is "Low", serial interface mode is started. At this time, all three ports, SCLK (synchronizing
transfer clock), SID (serial input data), and SOD (serial output data), are used. If S6A0073 is to be used with
other chips, chip select port (CS) can be used. By setting CS to "Low", S6A0073 can receive SCLK input. If CS is
set to "High", S6A0073 reset the internal transfer counter.
Before transfer real data, start byte has to be transferred. It is composed of succeeding 5 "High" bits, register
read write control bit (R/W), register selection bit (RS) and end bit that indicates the end of start byte. Whenever
succeeding 5 "High" bits are detected by S6A0073, it resets the serial transfer counter and prepares to receive
next information. The next input data is the register selection bit which determines which register will be used,
and read write control bit that determine the direction of data. Then end bit is transferred, which must have "Low"
value to show the end of start byte. (refer to Figure 19, Figure 20)
(1) Write Operation (R/W = 0)
After start byte is transferred from MPU to S6A0073, 8-bit data is transferred which is divided into 2 bytes, each
byte has 4 bit's real data and 4 bit's partition token data. For example, if real data is "10110001" (D0 - D7), then
serially transferred data becomes "1011 0000 0001 0000" where 2nd and 4th 4 bits must be "0000" for safe
transfer. To transfer several bytes continuously without changing RS bit and RW bit, start byte transfer is needed
only at first starting time, I, e, after first start byte is transferred, real data succeeding can be transferred.
(2) Read Operation (R/W = 1)
After start byte is transferred to S6A0073, MPU can receive 8-bit data through the SOD at a time from the LSB.
Waiting time is needed to insert between start byte and data reading, as internal reading from RAM requires
some delay. Continuous data reading is possible such as serial write operation. It also needs only one start bytes,
only if some delay between reading operations of each byte is inserted. During the reading operation, S6A0073
observes succeeding 5 "High" from MPU. If it is detected, S6A0073 restarts serial operation at once and prepares
to receive RS bit. So in continuous reading operation, SID port must be "low".
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