NEC PD78058FY(A) User Manual
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CHAPTER 16 SERIAL INTERFACE CHANNEL 0 (
µ
PD78058F SUBSERIES)
SCK0
D0
READY
SB0 (SB1)
D0
READY
SB0 (SB1)
ACK
BUSY
BUSY
ACK
9
"H"
SB0 (SB1)
SCK0
SCK0
"H"
SB0 (SB1)
Table 16-3. Various Signals in SBI Mode (1/2)
Timing Chart
Definition
Signal Name
Output
Device
Output
Condition
Effects on Flag
Meaning of Signal
CMD signal is output
to indicate that
transmit data is an
address.
i) Transmit data is an
address after REL
signal output.
ii) REL signal is not
output and trans-
mit data is an
command.
Low-level signal to be
output to SB0 (SB1) during
one-clock period of SCK0
after completion of serial
reception
[Synchronous BUSY signal]
Low-level signal to be
output to SB0 (SB1)
following Acknowledge
signal
Master/
slave
<1> BSYE = 0
<2> Execution of
instruction for
data write
to SIO0
(transfer start
instruction)
SB0 (SB1) rising edge
when SCK0 = 1
Master
Bus release
signal
(REL)
• RELT set
• RELD set
• CMDD clear
• CMDD set
• CMDT set
Master
Command
signal
(CMD)
SB0 (SB1) falling edge
when SCK0 = 1
Acknowledge
signal
(ACK)
<1> ACKE = 1
<2> ACKT set
• ACKD set
Completion of
reception
Slave
Busy signal
(BUSY)
• BSYE = 1
—
Serial receive disable
because of process-
ing
—
Serial receive enable
Slave
Ready signal
(READY)
High-level signal to be
output to SB0 (SB1) before
serial transfer start and
after completion of serial
transfer
[Synchronous BUSY output]