NEC uPD78P078 - Manual (Page 341)

CHAPTER 17 SERIAL INTERFACE CHANNEL 0 (
µ
PD78078 SUBSERIES)
341
(b) Serial bus interface control register (SBIC)
SBIC is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets SBIC to 00H.
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)
<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 (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 clock of SCK0 just after execution
of the instruction to be set 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 Output Control
0 Acknowledge signal automatic output disable (output with ACKT enable)
Acknowledge signal is output in synchronization with the 9th clock falling edge of
SCK0 (automatically output when ACKE = 1).
Before completion of
transfer
Acknowledge signal is output in synchronization with falling edge clock
of SCK0 just after execution of the instruction to be set 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