Rev. 1.00
100
September 11, 2018
Rev. 1.00
101
September 11, 2018
HT45F4050
A/D NFC Flash MCU
HT45F4050
A/D NFC Flash MCU
Single Pulse Output Mode
To select this mode, bits STM1 and STM0 in the STMC1 register should be set to 10 respectively
and also the STIO1 and STIO0 bits should be set to 11 respectively. The Single Pulse Output Mode,
as the name suggests, will generate a single shot pulse on the STM output pin.
The trigger for the pulse output leading edge is a low to high transition of the STON bit, which
can be implemented using the application program. However in the Single Pulse Output Mode, the
STON bit can also be made to automatically change from low to high using the external STCK pin,
which will in turn initiate the Single Pulse output. When the STON bit transitions to a high level, the
counter will start running and the pulse leading edge will be generated. The STON bit should remain
high when the pulse is in its active state. The generated pulse trailing edge will be generated when
the STON bit is cleared to zero, which can be implemented using the application program or when a
compare match occurs from Comparator A.
However a compare match from Comparator A will also automatically clear the STON bit and
thus generate the Single Pulse output trailing edge. In this way the CCRA value can be used to
control the pulse width. A compare match from Comparator A will also generate a STM interrupt.
The counter can only be reset back to zero when the STON bit changes from low to high when the
counter restarts. In the Single Pulse Output Mode CCRP is not used. The STCCLR and STDPX bits
are not used in this Mode.
STON bit
0
→
1
S/W Command
SET
“
STON
”
or
STCK Pin
Transition
STON bit
1
→
0
CCRA
Trailing Edge
S/W Command
CLR
“
STON
”
or
CCRA Compare
Match
STP Output Pin
Pulse Width = CCRA Value
CCRA
Leading Edge
Single Pulse Generation