Aeroflex Circuit Technology

SCDCT2500 REV A 6/12/98 Plainview NY (516) 694-6700

5

FIFORD

O

FIFO Read Bar

When the device is configured as a Source, this output pulses low during FIFOEN

mode enabling data from a FIFO to be loaded into the input data latch for

transmission.

RDYFORDTA

O

Ready For Data

This signal is high when the input data latch is available for new data to be loaded in.

When the data is loaded, RDYFORDTA goes low until the word is dumped into the

output shift register.

ENV

O

Envelope

This output envelopes the serial output data by being high during transmission.

TXDMXD

O

Transmit Data / Manchester Data

Serial NRZ data out or Manchester Data out depending on the TXSELECT mode.

TXCMXD

O

Transmit Clock / Manchester Data Bar

Output shift clock or Manchester Data Bar depending on the TXSELECT mode.

G20MHZ

O

Gated 20 Mhz

A gated 20 Mhz clock used in conjunction with Transmit Data, Transmit Clock and

Envelope to generate Manchester data using other Aeroflex encoders such as the

CT1698.

TXSELECT

I

Transmit Mode Select. (Internal Pulldown)

"1" = Serial output format is Manchester Data and Data Bar.

"0" = Output will be NRZ Data and Shift Clock.

RXDATA

I

Received Data

Received serial NRZ Data in.

RXCLOCK

I

Received Clock

Received Shift Clock In.

TEST

I

Test Mode Bar (Internal Pullup)

A low on this pin puts the device into an internal wrap-around test mode. Transmit Data

and Transmit Clock are internally connected to Received Data and Received Clock.

The circuit must be in Source mode and only 32 bit data loads and reads are allowed.

In this mode, STR2 loads the full 32 bits for transmission. When this word is wrapped

back, RCVDTA will pulse low indicating reception of a data or command word. STR1

enables the received data latch to be read out. Transmission of control frames can also

be tested in this mode using the regular LDCNTRL and RCVCNTRL signals.

BIT4IN

O

Bit Four In

Fourth bit of received Type E control frame.

BIT4OUT

I

Bit Four Out (Internal Pullup)

Fourth bit of Type E control frame to be transmitted.

SYNCIN

O

Sync In

Sync position of the Received Data Latch.

CFRMSYNC

O

Control Frame Sync In

Sync position of the Received Control Frame Latch

PRTYIN

O

Parity In

Parity bit position of the Received Data Latch.

I/O FUNCTION LISTING (Continued)

NAME

I/O

DESCRIPTION