5 Mode 1 parallel interface

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5.2

Output port

The eight bit parallel output port Q0-7 can be controlled by a transputer family device via the serial link.

QValid and QAck provide a simple two-wire handshake for this port.

A data packet received on the input link is presented on Q0-7; the link adaptor then takes QValid high to

initiate the handshake. After reading data from Q0-7, the peripheral device sets QAck high. The IMS C011

will then send an acknowledge packet out of the serial link to indicate a completed transaction and set

QValid low to complete the handshake.

Symbol

Parameter

Min

Nom

Max

Units

Notes

TLdVQvH

Start of link data to QValid

11.5

bits

1

TQdVQvH

Data setup

12

ns

2

TQvHQaH

QAck setup time from QValid high

0

ns

TQaHQvL

QAck high to QValid low

1.8

bits

1

TQaHLaV

QAck high to Ack on link

0.8

2.5

bits

1,3

TQvLQaL

QAck hold after QValid low

0

ns

TQvLQdX

Data hold

11

bits

1,4

Notes

1 Unit of measurement is one link data bit time; at 10 Mbits/s data link speed, one bit time is nomi-

nally 100 ns.

2 Where an existing data output bit is re-written with the same level there will be no glitch in the

output level.

3 Maximum time assumes there is no data packet already on the link. Maximum time with data on

the link is extended by 11 bits.

4 Data output remains valid until overwritten by new data.

Table 5.2

Mode 1 parallel data output

Ack

Data

Data

TLdVQvH

TQvHQaH

LinkIn

QValid

Q0–7

LinkOut

TQdVQvH

TQvLQdX

TQaHQvL

TQvLQaL

QAck

TQaHLaV

Figure 5.2

IMS C011 Mode 1 parallel data output from link adaptor