M38002M4 Datasheet, PDF (84/173 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Serial I/O
(2) Output of serial data (control of a peripheral IC)
Outline : 4-byte data is transmitted and received through the clock synchronous serial I/O. The CS
signal is output to a peripheral IC through the port P53.
P53
SCLK
TXD
CS
CLK
DATA
CS
CLK
DATA
3800 group
Peripheral IC
Fig. 2.3.19 Connection diagram [Output of serial data]
Specifications : • The Serial I/O is used. (clock synchronous serial I/O is selected)
• Synchronous clock frequency : 125 kHz (f(XIN) = 4 MHz is divided by 32)
• Transfer direction : LSB first
• The Serial I/O1 interrupt is not used.
• The Port P53 is connected to the CS pin (“L” active) of the peripheral IC for a
transmission control (the output level of the port P53 is controlled by software).
Figre 2.3.20 shows an output timing chart of serial data.
CS
CLK
DATA
DO0
DO1
DO2
DO3
Fig. 2.3.20 Timing chart [Output of serial data]
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3800 GROUP USER’S MANUAL