UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 489

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

conforming to the SBI are used.
Also, a pull-up resistor is necessary for the serial data bus line.
Figure 17-8 shows an example of a serial bus configuration in which CPUs and peripheral ICs that have a serial interface
With the SBI, since the SB0 serial data bus pin is an open-drain output, the serial data bus line is in the wired-OR state.
Caution When master/slave exchange processing is performed, since serial clock line (SCK) input/output
switching is performed asynchronously between master and slave, a pull-up resistor is also required
for the serial clock line (SCK).
Master CPU
Figure 17-8 Example of SBI Serial Bus Configuration
CHAPTER 17 CLOCKED SERIAL INTERFACE
SB0
SCK
Serial Data Bus
Serial Clock
+V
DD
SB0
SCK
SB0
SCK
SB0
SCK
SB0
SCK
Slave CPU
Address 1
Slave CPU
Address 2
Slave IC
Address 3
Slave IC
Address n
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