Quatech 802.11B/G manual SPI Protocol, SPI Read/Write Timing

Models: 802.11B/G

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Airborne Enterprise Module Databook

 

 

 

Quatech, Inc.

 

 

 

 

 

 

 

 

 

 

Table 13 - SPI AC Timings

 

 

 

 

 

 

 

 

 

 

 

 

 

Symbol

Parameter

Min

Typ

Max

 

Units

 

 

 

 

 

 

 

 

 

fMAX

Maximum Clock Frequency

 

 

8.00

 

MHz

 

 

 

 

 

 

 

 

 

tCS

SPI Select Low to Clock Rising Edge

100

 

 

 

ns

 

 

 

 

 

 

 

 

 

tCH

Clock High

62.5

 

 

 

ns

 

 

 

 

 

 

 

 

 

tCL

Clock Low

62.5

 

 

 

ns

 

 

 

 

 

 

 

 

 

tDA

Clock High to Data Out

 

 

60

 

ns

 

 

 

 

 

 

 

 

 

tDS

Clock Low to Data In Valid Set-up time

14

 

 

 

ns

 

 

 

 

 

 

 

 

 

tDH

Clock Low to Data Valid Hold time

2

 

 

 

ns

 

 

 

 

 

 

 

 

 

tCSH

Clock Falling Edge to SPI Select High

100

 

 

 

ns

 

 

 

 

 

 

 

 

 

tDELAY

SPI Select High to SPI Select Low

40

 

 

 

ns

 

 

 

 

 

 

 

 

Figure 3 - SPI Read/Write Timing

Figure 4 - SPI Clock and Select Timing

7.3SPI Protocol

A SPI message is composed of a 4 byte header followed by 0 or more bytes of data. The header data is full-duplex. That is, the Tx message header is sent to

100-8080-110

8/11/2009

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Quatech 802.11B/G manual SPI Protocol, SPI Read/Write Timing