Holtek HT45F23A Manual page 91

HT45F23A/HT45F24A
TinyPower Flash MCU with OPA & Comparators
TM
SIMD Register
Bit 7
Name D7
R/W R/W
POR x
Bit 7~0 D7~D0: SIM Data Register bit7~bit0
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 I
by the SPI function, only by the I
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.
SIMC0 Register
Bit
Name SIM2
R/W R/W
POR
SIM2, SIM1, SIM0: SIM Operating Mode Control
Bit 7~5
000: SPI master mode; SPI clock is f
001: SPI master mode; SPI clock is f
010: SPI master mode; SPI clock is f
011: SPI master mode; SPI clock is f
100: SPI master mode; SPI clock is Timer 0 output/2 (PFD0)
101: SPI slave mode
110: I
111: Unused mode
These bits setup the overall operating mode of the SIM function. As well as selecting
if the I
the SPI Master clock frequency. The SPI clock is a function of the system clock but
can also be chosen to be sourced from the Timer 0. If the SPI Slave Mode is selected
then the clock will be supplied by an external Master device.
Bit 4 PCKEN: PCK Output Pin Control
0: Disable
1: Enable
Bit 3~2 PCKP1, PCKP0: Select PCK output pin frequency
00: f
01: f
10: f
11: Timer 0 output/2 (PFD0)
Rev. 1.40
6 5
D6 D5
R/W R/W
x x
C function. Register SIMC0 is used to control the enable/disable
2
7 6 5
SIM1 SIM0 PCKEN
R/W R/W
1 1 1
C slave mode
2
C or SPI function, they are used to control the SPI Master/Slave selection and
2
SYS
/4
SYS
/8
SYS
91
4 3 2
D4 D3 D2
R/W R/W R/W
x x x
C function. The SIMC1 register is not used
2
4 3 2
PCKP1 PCKP0
R/W R/W R/W
0 0 0
/4
SYS
/16
SYS
/64
SYS
SUB
1 0
D1 D0
R/W R/W
x x
"x" unknown
1 0
SIMEN —
R/W —
0 —
March 29, 2019