Holtek BS66F340 - Page 122

Rev. 1.60 122 August 20, 2019 Rev. 1.60 123 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
Bit 5~4 STIO1~STIO0: Select STM external pin (STP or STPI) function
Compare Match Output Mode
00: No change
01: Output low
10: Output high
11: Toggle output
PWM Output Mode/Single Pulse Output Mode
00: PWM output inactive state
01: PWM output active state
10: PWM output
11: Single Pulse Output
Capture Input Mode
00: Input capture at rising edge of STPI
01: Input capture at falling edge of STPI
10: Input capture at rising/falling edge of STPI
11: Input capture disabled
Timer/Counter Mode
Unused
These two bits are used to determine how the STM output pin changes state when a
certain condition is reached. The function that these bits select depends upon in which
mode the STM is running.
In the Compare Match Output Mode, the STIO1 and STIO0 bits determine how the
STM output pin changes state when a compare match occurs from the Comparator
A. The TM output pin can be setup to switch high, switch low or to toggle its present
state when a compare match occurs from the Comparator A. When the bits are both
zero, then no change will take place on the output. The initial value of the STM output
pin should be setup using the STOC bit in the STMC1 register. Note that the output
level requested by the STIO1 and STIO0 bits must be different from the initial value
setup using the STOC bit otherwise no change will occur on the STM output pin when
a compare match occurs. After the STM output pin changes state, it can be reset to its
initial level by changing the level of the STON bit from low to high.
In the PWM Mode, the STIO1 and STIO0 bits determine how the STM output pin
changes state when a certain compare match condition occurs. The PWM output function
is modied by changing these two bits. It is necessary to only change the values of the
STIO1 and STIO0 bits only after the STM has been switched off. Unpredictable PWM
outputs will occur if the STIO1 and STIO0 bits are changed when the STM is running.
Bit 3 STOC: STM STP Output control
Compare Match Output Mode
0: Initial low
1: Initial high
PWM Output Mode/Single Pulse Output Mode
0: Active low
1: Active high
This is the output control bit for the STM output pin. Its operation depends upon
whether STM is being used in the Compare Match Output Mode or in the PWM
Mode/Single Pulse Output Mode. It has no effect if the STM is in the Timer/Counter
Mode. In the Compare Match Output Mode it determines the logic level of the STM
output pin before a compare match occurs. In the PWM Mode/Single Pulse Output
Mode it determines if the PWM signal is active high or active low.
Bit 2 STPOL: STM STP Output polarity control
0: Non-inverted
1: Inverted
This bit controls the polarity of the STP output pin. When the bit is set high the STM
output pin will be inverted and not inverted when the bit is zero. It has no effect if the
STM is in the Timer/Counter Mode.