Electronics America Computer Hardware User Manual

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Chapter 10 Clock Synchronous Serial Interface
10
Fig. 10-30 Sending Data from the Slave Device to the Master Device
Program processing
Hardware operation
Program processing
SCK pin
12345678 12
SB0 pin
BUSY READY D7
Hardware operation
D6 D5 D4 D3 D2 D1 D0 ACK BUSY D7 D6
READY
Data
Master device processing (receiver)
Transfer line Slave device processing (transmitter)
Read SIO
Read SIO
Set ACKT
Receive data processing
Stop SCK
Serial reception
Generate INTCSI
Output ACK
Serial reception
Write to SIO
Write to SIO
Clear BUSY
Serial transmission
Generate INTCSI
Set ACKD
Output BUSY
Clear BUSY
3
D5
Remark This timing is valid only under the following conditions:
• The master is only allowed to receive data.
ACKE is set to 0.
• The slave is only allowed to transmit data.
BSYE is set to 1.