Tm Exte�Nal Pins; Tm Input/Output Pin Cont�Ol - Holtek HT66F20-1 Manual

TM External Pins
Each of the TMs, irrespective of what type, has one TM input pin, with the label TCKn. The TM
input pin, is essentially a clock source for the TM and is selected using the TnCK2~TnCK0 bits in
the TMnC0 register. This external TM input pin allows an external clock source to drive the internal
TM. This external TM input pin is shared with other functions but will be connected to the internal
TM if selected using the TnCK2~TnCK0 bits. The TM input pin can be chosen to have either a
rising or falling active edge.
The TMs each have one or more output pins with the label TPn. When the TM is in the Compare
Match Output Mode, these pins can be controlled by the TM to switch to a high or low level or to
toggle when a compare match situation occurs. The external TPn output pin is also the pin where
the TM generates the PWM output waveform. As the TM output pins are pin-shared with other
function, the TM output function must first be setup using registers. A single bit in one of the
registers determines if its associated pin is to be used as an external TM output pin or if it is to have
another function. The number of output pins for each TM type and devices are different, the details
are provided in the accompanying table.
All TM output pin names have a "_n" suffix. Pin names that include a "_0" or "_1" suffix indicate
that they are from a TM with multiple output pins. This allows the TM to generate a complimentary
output pair, selected using the I/O register data bits.
Device
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HT�8F�0-1
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HT�8F�0-1
TM Input/Output Pin Control
Selecting to have a TM input/output or whether to retain its other shared function, is implemented
using one or two registers, with a single bit in each register corresponding to a TM input/output pin.
Setting the bit high will setup the corresponding pin as a TM input/output, if reset to zero the pin
will retain its original other function.
Device
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HT�8F�0-1
HT��F�0-1
HT�8F�0-1
Rev. 1.40
HT66F20-1/HT66F30-1/HT68F20-1/HT68F30-1
CTM STM
TCK0 TCK1
TP0_0 TP1_0� TP1_1
TCK0
―
TP0_0� TP0_1
TM Input/Output Pins
7 6 5
— — T1CP1
T1ACP0 — T1BCP1 T1BCP1
TM Input/Output Pin Control Registers List
78
Flash MCU with EEPROM
ETM
―
TCK1
TP1A� TP1B_0� TP1B_1
Bit
4 3 2
T1CP0 — —
— —
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Registers
TMPC0
TMPC0
1 0
— T0CP0
T0CP1 T0CP0