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CHAPTER 17 SERIAL INTERFACE IIC0 (
µ
PD780344Y, 780354Y SUBSERIES ONLY)
User’s Manual U15798EJ2V0UD
Figure 17-3. Format of IIC Control Register 0 (IICC0) (3/3)
SPT0
Stop condition trigger
0
Stop condition is not generated.
1
Stop condition is generated (termination of master device’s transfer).
After the SDA0 line goes to low level, either set the SCL0 line to high level or wait until it goes to
high level. Next, after the rated amount of time has elapsed, the SDA0 line changes from low level
to high level and a stop condition is generated.
Cautions concerning set timing
• For master reception:
Cannot be set during transfer.
Can be set only at the waiting period when ACKE0 has been set to 0
and slave has been notified of final reception.
• For master transmission: A stop condition cannot be generated normally during the ACK0 period. Therefore,
set it during the waiting period.
• Cannot be set at the same time as STT0.
• SPT0 can be set only when in master mode.
Note
• When WTIM0 has been set to 0, if SPT0 is set during the wait period that follows output of eight clocks, note
that a stop condition will be generated during the high level period of the ninth clock.
When a ninth clock must be output, WTIM0 should be changed from 0 to 1 during the wait period following
output of eight clocks, and SPT0 should be set during the wait period that follows output of the ninth clock.
Condition for clearing (SPT0 = 0)
Condition for setting (SPT0 = 1)
• Cleared by loss in arbitration
• Set by instruction
• Automatically cleared after stop condition is detected
• Cleared by LREL0 = 1
• When IICE0 = 0
• When RESET is input
Note
Set SPT0 only during master mode. However, you must set SPT0 and generate a stop condition before
the first stop condition is detected following the switch to operation enable status. For details, see
17.5.15
Other cautions
.
Caution
When bit 3 (TRC0) of IIC status register 0 (IICS0) is set to 1, WREL0 is set during the ninth clock
and wait is canceled, after which TRC0 is cleared and the SDA0 line is set to high impedance.
Remarks 1.
STD0:
Bit 1 of IIC status register 0 (IICS0)
ACKD0: Bit 2 of IIC status register 0 (IICS0)
TRC0:
Bit 3 of IIC status register 0 (IICS0)
COI0:
Bit 4 of IIC status register 0 (IICS0)
EXC0:
Bit 5 of IIC status register 0 (IICS0)
MSTS0: Bit 7 of IIC status register 0 (IICS0)
2.
Bits 0 and 1 (SPT0, STT0) become 0 when they are read after data setting.
Содержание mPD780344 Series
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