Rev. 1.50
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Rev. 1.50
139
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HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
SIMC0 Register
Bit
7
6
5
4
3
2
1
0
Name
SIM�
SIM1
SIM0
—
SIMDEB1 SIMDEB0 SIMEN
SIMICF
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
R/W
POR
1
1
1
—
0
0
0
0
Bit 7~5
SIM2~SIM0
: SIM Operating Mode Control
000: SPI master mode; SPI clock is f
SYS
/4
001: SPI master mode; SPI clock is f
SYS
/16
010: SPI master mode; SPI clock is f
SYS
/64
011: SPI master mode; SPI clock is f
TBC
100: SPI master mode; SPI clock is TM1 CCRP match frequency/2
101: SPI slave mode
110: I
2
C slave mode
111: Non SIM function
These bits setup the overall operating mode of the SIM function. As well as selecting
if the I
2
C or SPI function, they are used to control the SPI Master/Slave selection and
the SPI Master clock frequency. The SPI clock is a function of the system clock but
can also be chosen to be sourced from TM1. If the SPI Slave Mode is selected then the
clock will be supplied by an external Master device.
Bit 4
Unimplemented, read as “0”
Bit 3~2
SIMDEB1~SIMDEB0
: I
2
C Debounce Time Selection
00: No debounce
01: 2 system clock debounce
1x: 4 system clock debounce
Bit 1
SIMEN
: SIM Enable Control
0: Disable
1: Enable
The bit is the overall on/off control for the SIM interface. When the SIMEN bit is
cleared to zero to disable the SIM interface, the SDI, SDO, SCK and SCS, or SDA and
SCL lines will lose their SPI or I
2
C function and the SIM operating current will be
reduced to a minimum value. When the bit is high the SIM interface is enabled. If the
SIM is configured to operate as an SPI interface via the SIM2~SIM0 bits, the contents
of the SPI control registers will remain at the previous settings when the SIMEN bit
changes from low to high and should therefore be first initialised by the application
program. If the SIM is configured to operate as an I
2
C interface via the SIM2~SIM0
bits and the SIMEN bit changes from low to high, the contents of the I
2
C control bits
such as HTX and TXAK will remain at the previous settings and should therefore be
first initialised by the application program while the relevant I
2
C flags such as HCF,
HAAS, HBB, SRW and RXAK will be set to their default states.
Bit 0
SIMICF
: SIM Incomplete Flag
0: SIM incomplete condition not occurred
1: SIM incomplete condition occured
This bit is only available when the SIM is configured to operate in an SPI slave mode.
If the SPI operates in the slave mode with the SIMEN and CSEN bits both being set
to 1 but the SCS line is pulled high by the external master device before the SPI data
transfer is completely finished, the SIMICF bit will be set to 1 together with the TRF
bit. When this condition occurs, the corresponding interrupt will occur if the interrupt
function is enabled. However, the TRF bit will not be set to 1 if the SIMICF bit is set
to 1 by software application program.