©Copyright 2000-2007 SD Card Association

SDIO Simplified Specification Version 2.00

6.14Bus State Diagram

Figure 6-2 shows the Bus State Diagram for an SDIO card. It shows the bus states and their relations to SDIO commands and Suspend/Resume.

Commands

accepted in “STB”

CMD3, CMD7,

CMD15

 

 

 

 

 

 

 

 

Commands

 

 

 

 

 

 

 

 

 

 

 

 

 

 

accepted in “INI”

 

 

 

 

 

 

 

 

 

 

 

Initialization

 

CMD5, CMD3

 

 

 

 

 

 

Power On

 

 

 

 

CMD15

 

 

 

 

 

 

 

 

 

State

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CMD3

CMD52 Reset

 

 

CMD52 Reset

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Commands

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

accepted in “TRN”

 

 

 

 

 

 

 

 

 

Transfer

 

CMD52

 

Standby

 

 

 

CMD53 (to valid

State

 

 

 

State

CMD7 with

function)

(Dat Bus Active)

 

 

 

 

 

 

Function

BS=1

 

 

 

 

 

 

incorrect RCA

Resume

 

 

 

 

 

 

 

 

CMD7 with

 

 

 

 

 

Execution complete

 

 

 

 

 

 

 

 

 

Function Suspend

 

 

 

correct RCA

 

 

Command

 

 

 

 

 

CMD52 Abort

 

 

 

 

 

 

 

 

State

 

 

 

 

 

 

 

 

 

 

 

 

(Dat Bus Free)

CMD15 or OCR

 

Inactive

 

 

 

 

 

BS=0

 

 

 

 

 

 

mismatch

 

 

State

 

 

 

 

 

 

 

 

 

 

Commands

 

 

 

 

 

 

 

 

 

CMD7 with correct

 

 

 

 

 

 

 

accepted in “CMD”

 

 

 

 

 

 

 

 

 

 

RCA

 

 

 

 

 

 

 

CMD7, CMD52,

 

 

CMD53 to invalid function can be:

 

 

CMD53 to invalid

 

CMD53, CMD15

 

 

 

 

function

y I/O Disable or I/O Not Ready (IORDY=0)

 

 

 

 

 

 

 

y I/O Function number error in response y I/O Function already Suspended

Figure 6-2 State Diagram for Bus State Machine

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SDI Technologies SDIO Card manual Bus State Diagram, State Diagram for Bus State Machine