DSP56300FM View Datasheet(PDF) - Freescale Semiconductor

Part Name

Description

Manufacturer

DSP56300FM

24-Bit Audio Digital Signal Processor

Freescale Semiconductor 

Serial Host Interface

Table 2-9 Serial Host Interface Signals (continued)

Signal

Name

HA0

Signal

Type

Input

State During

Reset

Signal Description

Tri-stated

I2C Slave Address 0—This signal uses a Schmitt-trigger input when configured for the

I2C mode. When configured for I2C slave mode, the HA0 signal is used to form the

slave device address. HA0 is ignored when configured for the I2C master mode.

This signal is tri-stated during hardware, software, and individual reset. Thus, there is

no need for an external pull-up in this state.

This input is 5 V tolerant.

SS

Input

HA2

Input

Input

Input

SPI Slave Select—This signal is an active low Schmitt-trigger input when configured

for the SPI mode. When configured for the SPI Slave mode, this signal is used to enable

the SPI slave for transfer. When configured for the SPI master mode, this signal should

be kept deasserted (pulled high). If it is asserted while configured as SPI master, a bus

error condition is flagged. If SS is deasserted, the SHI ignores SCK clocks and keeps

the MISO output signal in the high-impedance state.

I2C Slave Address 2—This signal uses a Schmitt-trigger input when configured for the

I2C mode. When configured for the I2C Slave mode, the HA2 signal is used to form the

slave device address. HA2 is ignored in the I2C master mode.

This signal is tri-stated during hardware, software, and individual reset. Thus, there is

no need for an external pull-up in this state.

This input is 5 V tolerant.

HREQ

Input or

Output

Tri-stated

Host Request—This signal is an active low Schmitt-trigger input when configured for

the master mode but an active low output when configured for the slave mode.

When configured for the slave mode, HREQ is asserted to indicate that the SHI is ready

for the next data word transfer and deasserted at the first clock pulse of the new data

word transfer. When configured for the master mode, HREQ is an input. When asserted

by the external slave device, it will trigger the start of the data word transfer by the

master. After finishing the data word transfer, the master will await the next assertion of

HREQ to proceed to the next transfer.

This signal is tri-stated during hardware, software, personal reset, or when the

HREQ1–HREQ0 bits in the HCSR are cleared. There is no need for external pull-up in

this state.

This input is 5 V tolerant.

DSP56364 Technical Data, Rev. 4.1

2-8

Freescale Semiconductor

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