NEC 78K0 Series User Manual page 420

Address: FFABH After reset: 00H
<7>
Symbol
IICF0 STCF IICBSY
STCF
0
Generate start condition
1
Start condition generation unsuccessful: clear STT0 flag
Condition for clearing (STCF = 0)
• Cleared by STT0 = 1
• When IICE0 = 0 (operation stop)
• Reset
IICBSY
0
Bus release status (communication initial status when STCEN0 = 1)
1 Bus communication status (communication initial status when STCEN0 = 0)
Condition for clearing (IICBSY = 0)
• Detection of stop condition
• When IICE0 = 0 (operation stop)
• Reset
STCEN
0
After operation is enabled (IICE0 = 1), enable generation of a start condition upon detection of
a stop condition.
1 After operation is enabled (IICE0 = 1), enable generation of a start condition without detecting
a stop condition.
Condition for clearing (STCEN = 0)
• Detection of stop condition
• Reset
IICRSV
0 Enable communication reservation
1 Disable communication reservation
Condition for clearing (IICRSV = 0)
• Cleared by instruction
• Reset
Note Bits 6 and 7 are read-only.
Cautions 1. Write to STCEN only when the operation is stopped (IICE0 = 0).
2. As the bus release status (IICBSY = 0) is recognized regardless of the actual bus
3. Write to IICRSV only when the operation is stopped (IICE0 = 0).
Remark STT0: Bit 1 of IIC control register 0 (IICC0)
IICE0: Bit 7 of IIC control register 0 (IICC0)
420
CHAPTER 17 SERIAL INTERFACE IIC0
Figure 17-7. Format of IIC Flag Register 0 (IICF0)
Note
R/W
<6> 5 4
0 0
Communication reservation function disable bit
status when STCEN = 1, when generating the first start condition (STT0 = 1), it is
necessary to verify that no third party communications are in progress in order to
prevent such communications from being destroyed.
Preliminary User's Manual U17260EJ3V1UD
3 2 <1>
0 0 STCEN IICRSV
STT0 clear flag
Condition for setting (STCF = 1)
• Generating start condition unsuccessful and STT0
cleared to 0 when communication reservation is
disabled (IICRSV = 1).
2
I C bus status flag
Condition for setting (IICBSY = 1)
• Detection of start condition
• Setting of IICE0 when STCEN = 0
Initial start enable trigger
Condition for setting (STCEN = 1)
• Set by instruction
Condition for setting (IICRSV = 1)
• Set by instruction
<0>