9 swi, Figure 3. ser – Cirrus Logic CS49DV8C User Manual

Page 14

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Copyright 2008 Cirrus Logic, Inc.

DS868PP2

CS49DV8C Data Sheet
32-bit Audio DSP Family

5.9 Switching Characteristics — Serial Control Port - SPI Slave Mode

.

Figure 3. Serial Control Port - SPI Slave Mode Timing

Parameter

Symbol

Min

Typical

Max

Units

SCP_CLK frequency

1

1. The specification f

spisck

indicates the maximum speed of the hardware. The system designer should be aware that the

actual maximum speed of the communication port may be limited by the firmware application. Flow control using the
SCP_BSY pin should be implemented to prevent overflow of the input data buffer.At boot the maximum speed is
Fxtal/3.

f

spisck

-

25

MHz

SCP_CS falling to SCP_CLK rising

t

spicss

24

-

ns

SCP_CLK low time

t

spickl

20

-

ns

SCP_CLK high time

t

spickh

20

-

ns

Setup time SCP_MOSI input

t

spidsu

5

-

ns

Hold time SCP_MOSI input

t

spidh

5

-

ns

SCP_CLK low to SCP_MISO output valid

t

spidov

-

11

ns

SCP_CLK falling to SCP_IRQ rising

t

spiirqh

-

20

ns

SCP_CS rising to SCP_IRQ falling

t

spiirql

0

ns

SCP_CLK low to SCP_CS rising

t

spicsh

24

-

ns

SCP_CS rising to SCP_MISO output high-Z

t

spicsdz

-

20

ns

SCP_CLK rising to SCP_BSY falling

t

spicbsyl

-

3

*

DCLKP+20

ns

SCP_BSY

SCP_CS

SCP_CLK

SCP_MOSI

SCP_MISO

SCP_IRQ

0

1

2

6

7

0

5

6

7

t

spicss

t

spickl

t

spickh

t

spidsu

t

spidh

t

spidov

A6

A5

A0

R/W

MSB

LSB

MSB

LSB

t

spicsh

t

spibsyl

t

spiirql

t

spiirqh

f

spisck

t

spicsdz

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