Holtek BS66F340 - Page 164

Rev. 1.60 164 August 20, 2019 Rev. 1.60 165 August 20, 2019
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
• SIMD Register
The SIMD register is used to store the data being transmitted and received. The same register is used
by both the SPI and I
2
C functions. Before the device writes data to the I
2
C bus, the actual data to
be transmitted must be placed in the SIMD register. After the data is received from the I
2
C bus, the
device can read it from the SIMD register. Any transmission or reception of data from the I
2
C bus
must be made via the SIMD register.
Bit 7 6 5 4 3 2 1 0
Name D7 D6 D5 D4 D3 D2 D1 D0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
POR x x x x x x x x
"x": unknown
• SIMA Register
The SIMA register is also used by the SPI interface but has the name SIMC2. The SIMA register is
the location where the 7-bit slave address of the slave device is stored. Bits 7~1 of the SIMA register
dene the device slave address. Bit 0 is not dened.
When a master device, which is connected to the I
2
C bus, sends out an address, which matches the
slave address in the SIMA register, the slave device will be selected. Note that the SIMA register is
the same register address as SIMC2 which is used by the SPI interface.
Bit 7 6 5 4 3 2 1 0
Name IICA6 IICA5 IICA4 IICA3 IICA2 IICA1 IICA0 D0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
POR x x x x x x x x
"x": unknown
Bit 7~1 IICA6~IICA0: I
2
C slave address
IICA6~IICA0 is the I
2
C slave address bit 6 ~ bit 0
Bit 0 Undened bit
The bit can be read or written by the application program.
There are also two control registers for the I
2
C interface, SIMC0 and SIMC1. The register SIMC0
is used to control the enable/disable function and to set the data transmission clock frequency.The
SIMC1 register contains the relevant ags which are used to indicate the I
2
C communication status.
• SIMC0 Register
Bit 7 6 5 4 3 2 1 0
Name SIM2 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
SUB
100: SPI master mode; SPI clock is CTM0 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 TM0. If the SPI Slave Mode is selected then the
clock will be supplied by an external Master device.