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 1
STDPX
: STM PWM duty/period control
0: CCRP – period; CCRA – duty
1: CCRP – duty; CCRA – period
This bit determines which of the CCRA and CCRP registers are used for period and
duty control of the PWM waveform.
Bit 0
STCCLR
: STM Counter Clear condition selection
0: Comparator P match
1: Comparator A match
This bit is used to select the method which clears the counter. Remember that the
Standard TM contains two comparators, Comparator A and Comparator P, either of
which can be selected to clear the internal counter. With the STCCLR bit set high,
the counter will be cleared when a compare match occurs from the Comparator A.
When the bit is low, the counter will be cleared when a compare match occurs from
the Comparator P or with a counter overflow. A counter overflow clearing method can
only be implemented if the CCRP bits are all cleared to zero. The STCCLR bit is not
used in the PWM Output, Single Pulse Output or Capture Input Mode.
• STMRP Register
Bit
7
6
5
4
3
2
1
0
Name
STRP7
STRP6
STRP5
STRP4
STRP3
STRP2
STRP1
STRP0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~0
STRP7~STRP0
: STM CCRP 8-bit register, compared with the STM counter bit 15~bit 8
Comparator P match period =
0: 65536 STM clocks
1~255: (1~255)
×
256 STM clocks
These eight bits are used to setup the value on the internal CCRP 8-bit register, which
are then compared with the internal counter’s highest eight bits. The result of this
comparison can be selected to clear the internal counter if the STCCLR bit is set to zero.
Setting the STCCLR bit to zero ensures that a compare match with the CCRP values
will reset the internal counter. As the CCRP bits are only compared with the highest
eight counter bits, the compare values exist in 256 clock cycle multiples. Clearing all
eight bits to zero is in effect allowing the counter to overflow at its maximum value.
Standard Type TM Operation Modes
The Standard Type TM can operate in one of five operating modes, Compare Match Output Mode,
PWM Output Mode, Single Pulse Output Mode, Capture Input Mode or Timer/Counter Mode. The
operating mode is selected using the STM1 and STM0 bits in the STMC1 register.
Compare Match Output Mode
To select this mode, bits STM1 and STM0 in the STMC1 register, should be set to 00 respectively.
In this mode once the counter is enabled and running it can be cleared by three methods. These are
a counter overflow, a compare match from Comparator A and a compare match from Comparator P.
When the STCCLR bit is low, there are two ways in which the counter can be cleared. One is when
a compare match from Comparator P, the other is when the CCRP bits are all zero which allows the
counter to overflow. Here both STMAF and STMPF interrupt request flags for Comparator A and
Comparator P respectively, will both be generated.
If the STCCLR bit in the STMC1 register is high then the counter will be cleared when a compare
match occurs from Comparator A. However, here only the STMAF interrupt request flag will be
generated even if the value of the CCRP bits is less than that of the CCRA registers. Therefore when
STCCLR is high no STMPF interrupt request flag will be generated. In the Compare Match Output
Mode, the CCRA can not be set to "0".