Rev. 1.50
144
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Rev. 1.50
145
����st ��� �01�
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
I C t i m e - o u t
c o u n t e r s t a r t
I C t i m e - o u t c o u n t e r r e s e t
o n S C L n e g a t i v e t r a n s i t i o n
1
0
1
0
0
1
0
0
1
0
0
1
0
1
0
1
1
S C L
S t a r t
S D A
S R W
A C K
S t o p
S C L
S D A
S l a v e A d d r e s s
2
2
I
2
C Time-out
When an I
2
C time-out counter overflow occurs, the counter will stop and the SIMTOEN bit will
be cleared to zero and the SIMTOF bit will be set high to indicate that a time-out condition has
occurred. The time-out condition will also generate an interrupt which uses the I
2
C interrrupt vector.
When an I
2
C time-out occurs, the I
2
C internal circuitry will be reset and the registers will be reset
into the following condition:
Register
After I
2
C Time-out
SIMD� SIM�� SIMC0
No chan�e
SIMC1
Reset to POR condition
I
2
C Register after Time-out
The SIMTOF flag can be cleared by the application program. There are 64 time-out period selections
which can be selected using the SIMTOS bits in the SIMTOC register. The time-out duration is
calculated by the formula: ((1~64) × (32/f
SUB
)). This gives a time-out period which ranges from
about 1ms to 64ms.
SIMTOC Register
Bit
7
6
5
4
3
2
1
0
Name
SIMTOEN SIMTOF SIMTOS5 SIMTOS4 SIMTOS3 SIMTOS� SIMTOS1 SIMTOS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7
SIMTOEN
: SIM I
2
C Time-out function control
0: Disable
1: Enable
Bit 6
SIMTOF
: SIM I
2
C Time-out flag
0: No time-out occurred
1: Time-out occurred
Bit 5~0
SIMTOS5~SIMTOS0
: SIM I
2
C Time-out period selection
I
2
C Time-out clock source is f
SUB
/32
I
2
C Time-out period is equal to (SIMTOS[5:0] + 1) × 32
f
SUB
