MC68LC302 Datasheet, PDF(112/169 Page) Motorola, Inc – Low Power Integrated Multiprotocol Processor Reference Manual

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MC68LC302 Datasheet, PDF (112/169 Pages) Motorola, Inc – Low Power Integrated Multiprotocol Processor Reference Manual

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Signal Description

MC68302 Userâs Manual for details. CD1 may also be used as an external sync in NMSI

mode.

CTS1/L1GRâClear to Send/Layer-1 Grant

This input is the NMSI1 CTS signal in the NMSI mode or the grant signal in the IDL/GCI

mode. If this pin is not used as a grant signal in GCI mode, it should be connected to VDD.

If the CTS1 pin has changed for more than one transmit clock cycle, the LC302 asserts

the appropriate bit in the SCC1 event register and optionally aborts the transmission of

that frame.

If SCC1 is programmed not to support CTS1 (in the SCC1 mode register), then this pin

may be used as an external interrupt source. The current value of the CTS1 pin may be

read in the SCCS1 register. See the MC68302 Userâs Manual for details.

RTS1/L1RQ/GCIDCLâRequest to Send/Layer-1 Request/GCI Clock Out

This output is the NMSI1 RTS signal in NMSI mode or PCM Highway mode, the IDL re-

quest signal in IDL mode, or the GCI data clock output in GCI mode. In PCM Highway

mode, RTS1 is asserted high.

RTS1 is asserted when SCC1 (in NMSI mode) has data or pad (flags or syncs) to transmit.

In GCI mode this pin is used to output the GCI data clock.

5.14 NMSI2 PORT OR PORT A PINS

The NMSI2 port or port A pins are shown in Figure 5-10.

RXD2/PA0

TXD2/PA1

RCLK2/PA2

TCLK2/PA3

CTS2/PA4

RTS2/PA5

CD2/PA6

BRG2/SDG2/PA7

Figure 5-10. NMSI2 Port or Port A Pins

These eight pins can be used either as the NMSI2 port or as a general-purpose parallel I/O

port. Each one of these pins can be configured individually to be general-purpose I/O pins

or a dedicated function in NMSI2. When they are used as NMSI2 pins, they function exactly

as the NMSI1 pins in NMSI mode.

The PA7 signal in dedicated mode becomes serial data strobe 2 (SDS2) in IDL and GCI

modes. In IDL/GCI modes, the SDS2âSDS1 outputs may be used to route the B1 and/or B2

channels to devices that do not support the IDL or GCI buses. This is configured in the SI-

MOTOROLA

MC68LC302 REFERENCE MANUAL

5-17

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