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Rev. 2.50
236
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Rev. 2.50
23�
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HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
UART Module Pin Description
Pin Name
I/O
Description
RX
I
External UART RX serial data inp�t pin
If UARTEN=� and RXEN=�� then RX is the UART serial data inp�t
If UARTEN=0 or RXEN=0� then RX is high impedance
TX
O
External UART TX serial data o�tp�t pin
If UARTEN=� and TXEN=�� then TX is the UART serial data o�tp�t
If UARTEN=0 or TXEN=0� then TX is high impedance
SDI
I
Internal Slave SPI Serial Data In Inp�t Signal
Internally connected to the MCU Master SPI SDO o�tp�t signal
SDO
O
Internal Slave SPI Serial Data O�t O�tp�t Signal
Internally connected to the MCU Master SPI SDI inp�t signal
SCK
I
Internal Slave SPI Serial Clock Inp�t Signal
Internally connected to the MCU Master SPI SCK o�tp�t signal
SCS
I
Internal Slave SPI Device Select Inp�t Signal
Internally connected to the MCU Master SPI SCS o�tp�t signal -- connected to p�ll high resistor
CLKI
I
Internal Clock Inp�t Signal
Internally connected to the MCU Master PCK o�tp�t signal
INT
O
Internal UART Interr�pt O�tp�t Signal
Internally connected to the MCU Master PINT inp�t signal
A UART related interr�pt will generate a low p�lse signal on this line
NC
—
Implies that the pin is Not Connected and can therefore not be �sed.
Notes: The pin description for all pins with the exception of the UART TX and RX pins are described in the
preceding MCU section.