CS4953xx Data Sheet

32-bit Audio Decoder DSP Family

DS705F2

14

5.10 Switching Characteristics — Serial Control Port - SPI Slave Mode

Parameter

Symbol

Min

Typical

Max

Units

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

2. When SCP1 is in SPI slave mode, very slow rise and fall times of the SCP_CLK edges may make the edges of the

SCP_CLK more susceptible to noise, resulting in non-smooth edges. Any glitch at the threshold levels of the SCP

port input signals could result in abnormal operation of the port.

In systems that have noise coupling onto SCP_CLK, slow rise and fall times may cause host communication

problems. Increasing rise time makes host communication more reliable.

——

25

MHz

SCP_CS falling to SCP_CLK rising2

24

—

—

ns

SCP_CLK low time2

20

—

—

ns

SCP_CLK high time2

20

—

—

ns

Setup time SCP_MOSI input

5—

—

ns

Hold time SCP_MOSI input

5—

—

ns

SCP_CLK low to SCP_MISO output valid2

——

11

ns

SCP_CLK falling to SCP_IRQ rising2

—

—

20

ns

SCP_CS rising to SCP_IRQ falling2

0—

—

ns

SCP_CLK low to SCP_CS rising2

24

—

—

ns

SCP_CS rising to SCP_MISO output high-Z

—20

—

ns

SCP_CLK rising to SCP_BSY falling2

—

ns