SERCON816

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RxD

14

I

Receive data for the serial interface.

RxC

12

O

Receive clock for the serial interface. Output of the internally generated

receive clock.

RECACTN

26

O

Receive active, active low. Indicates that the serial receiver is receiving a

telegram.

TxD1

16

O

Transmit data. The pin can be switched to a high impedance state.

TxD6-2

22,21,20,

18,17

O

Transmit data or output port. The pins either output the serial data or can be

used as parallel output ports. When they output transmit data, each pin can be

switched to a high impedance state individually.

TxC

13

O

Transmit clock for the serial interface. Output for the internally generated

transmit clock.

IDLE

25

O

Transmitter active, active low. When transmitting own data IDLE is 0.

DMAREQT

39

O

DMA request transmit, active high: becomes active when data can be written

to the transmit FIFO. DMAREQT becomes inactive again at the beginning of

the last write access to the transmit FIFO.

DMAACKTN

41

I

DMA acknowledge transmit, active low: when DMAACKTN is 0, the transmit

FIFO is written to when there is a bus write access independent of the levels

on A6-1 and the chip select signals.

ADMUX

96

I

Address data bus: when ADMUX is 0 A15-0 are the address inputs, when

ADMUX is 1 A15-0 are the outputs of the address latch.

BUSMODE0,

BUSMODE1

97,98

I

Bus mode: BUSMODE0 = 0 turns on the Intel bus interface (RDN = read,

WRN = write), BUSMODE0 = 1 selects the Motorola interface (RDN = data

strobe, WRN = read/write). BUSMODE1 selects the 0-active data strobe

(BUSMODE1 = 0) or the 1-active data strobe (BUSMODE1 = 1).

BUSWIDTH

99

I

Bus width: selects the 8-bit- (0) or the 16-bit-wide interface (1).

BYTEDIR

100

I

Byte address sequence: when BYTEDIR is 0, A0 = 0 addresses the lower 8

bits of a word (low byte first), when BYTEDIR is 1, the upper 8 bits of a word

are addressed (high byte first).

INT0, INT1

44,43

O

Interrupts, active low or active high. Interrupt sources and signal polarity are

programmable.

SBAUD16

28

I

Baud rate and SERCON410B compatible mode: SBAUD and SBAUD16

selects the baud rate for the serial interface. If SBAUD16 is ‘1’ the

SERCON410B compatible mode is selected.

SBAUD

29

I

Baud rate. Can be overwritten by the microprocessor.

RxD

14

I

Receive data for the serial interface.

RxC

12

O

Receive clock for the serial interface. Output of the internally generated

receive clock.

RECACTN

26

O

Receive active, active low. Indicates that the serial receiver is receiving a

telegram.

TxD1

16

O

Transmit data. The pin can be switched to a high impedance state.

TxD6-2

22,21,20,

18,17

O

Transmit data or output port. The pins either output the serial data or can be

used as parallel output ports. When they output transmit data, each pin can be

switched to a high impedance state individually.

TxC

13

O

Transmit clock for the serial interface. Output for the internally generated

transmit clock.

IDLE

25

O

Transmitter active, active low. When transmitting own data IDLE is 0.

TM0, TM1

30,31

I

Turn on test generator: TM0 = 0 switches TxD1-6 to contiuous signal light,

TM1 = 0 switch-over to zero bit stream. The processor can overwrite the level

of TM1-0. Select repeater mode at reset time: TM1=0 and TM2=0 repeater

off, all other repeater on.

Table 1. SERCON816 I/O Port Function Summary (continued)

Signal(s)

Pin(s)

IO

Function