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CHAPTER 16 SERIAL INTERFACE CHANNEL 0 (
μ
PD780058 Subseries)
(b) Serial bus interface control register (SBIC)
SBIC is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input clears SBIC to 00H.
The shaded area is used in the SBI mode.
Note
Bits 2, 3, and 6 (RELD, CMDD and ACKD) are read-only bits.
Remarks 1.
Bits 0, 1, and 4 (RELT, CMDT, and ACKT) are 0 when read after data setting.
2.
CSIE0: Bit 7 of serial operating mode register 0 (CSIM0)
(Cont’d)
6
5
4
3
2
1
0
7
Symbol
SBIC
BSYE ACKD ACKE ACKT CMDD RELD CMDT RELT
RELT
Used for bus release signal output.
When RELT = 1, SO0 Iatch is set to (1). After SO0 latch setting, automatically cleared to (0).
Also cleared to 0 when CSIE0 = 0.
R/W
FF61H 00H
R/W
Note
Address After Reset R/W
CMDT
Used for command signal output.
When CMDT = 1, SO0 Iatch is cleared to (0). After SO0 latch clearance, automatically cleared to (0).
Also cleared to 0 when CSIE0 = 0.
R/W
R
RELD
Bus Release Detection
Set Conditions (RELD = 1)
Clear Conditions (RELD = 0)
When bus release signal (REL) is detected
When transfer start instruction is executed
If SIO0 and SVA values do not match in address
reception (only when WUP = 1)
When CSIE0 = 0
When RESET input is applied
R
CMDD
Command Detection
Clear Conditions (CMDD = 0)
When transfer start instruction is executed
When bus release signal (REL) is detected
When CSIE0 = 0
When RESET input is applied
Set Conditions (CMDD = 1)
When command signal (CMD) is detected
Acknowledge signal is output in synchronization with the falling edge of SCK0 clock just after execution
of the instruction that sets this bit to 1 and, after acknowledge signal output, automatically cleared to (0).
Used as ACKE = 0. Also cleared to (0) upon start of serial interface transfer or when CSIE0 = 0.
R/W
ACKE
Acknowledge Signal Automatic Output Control
0
Acknowledge signal automatic output disable (output with ACKT enable)
Acknowledge signal is output in synchronization with the falling edge of the 9th
SCK0 clock (automatically output when ACKE = 1).
Before completion of
transfer
Acknowledge signal is output in synchronization with falling edge of SCK0 clock
just after execution of the instruction that sets this bit to 1
(automatically output when ACKE = 1).
However, not automatically cleared to 0 after acknowledge signal output.
After completion of
transfer
1
R/W
ACKT