HT46R068B/HT46R069B
Enhanced A/D Type 8-bit OTP MCU
SPI Registers
There are three internal registers which control the overall operation of the SPI interface. These are
the SIMD data register and two registers SIMC0 and SIMC2. Note that the SIMC1 register is only
used by the I2C interface.
Bit
Register
Name
7
SIMꢃ
D7
6
SIM1
Dꢄ
5
SIM0
D5
4
3
2
1
0
—
D0
TRF
SIMC0
SIMD
PCKEN
D4
PCKP1
D3
MLS
PCKP0
Dꢃ
CSEN
SIMEN
D1
WCOL
SIMCꢃ
D7
Dꢄ
CKPOLB
CKEG
SIM Registers List
The SIMD register is used to store the data being transmitted and received. The same register is
used by both the SPI and I2C functions. Before the device writes data to the SPI bus, the actual
data to be transmitted must be placed in the SIMD register. After the data is received from the SPI
bus, the device can read it from the SIMD register. Any transmission or reception of data from the
SPI bus must be made via the SIMD register.
● SIMD Regisater
Bit
Name
R/W
7
D7
R/W
x
6
Dꢄ
R/W
x
5
D5
R/W
x
4
D4
R/W
x
3
D3
R/W
x
2
Dꢃ
R/W
x
1
D1
R/W
x
0
D0
R/W
x
POR
"x" ꢀnknown
There are also two control registers for the SPI interface, SIMC0 and SIMC2. Note that the SIMC2
register also has the name SIMA which is used by the I2C function. The SIMC1 register is not
used by the SPI function, only by the I2C function. Register SIMC0 is used to control the enable/
disable function and to set the data transmission clock frequency. Although not connected with the
SPI function, the SIMC0 register is also used to control the Peripheral Clock Prescaler. Register
SIMC2 is used for other control functions such as LSB/MSB selection, write collision flag etc.
Rev. 1.00
8ꢃ
�anꢀaꢁꢂ ꢃꢄꢅ ꢃ011
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
