5 mmc_cmdat register (mmc_cmdat), 5 mmc_cmdat register (mmc_cmdat) -26, Mmc_cmdat bit definitions -26 – Intel PXA255 User Manual

Page 528

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15-26

Intel® PXA255 Processor Developer’s Manual

MultiMediaCard Controller

15.5.5

MMC_CMDAT Register (MMC_CMDAT)

MMC_CMDAT, shown in

Table 15-9

, controls the command sequence. Writing to this register

starts the command sequence on the MMC bus when the MMC bus clock is turned on.

This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.

0

SPI_EN

SPI Mode Enable

0 –

Disables SPI mode

1 –

Enables SPI mode

Table 15-8. MMC_SPI Bit Definitions (Sheet 2 of 2)

Physical Address

0x4110_000c

MMC_SPI Register

MultiMediaCard Controller

Bit

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

0

reserved

SPI_

C

S_

AD

DR

ESS

SPI_

C

S_

EN

CR

C_

O

N

SP

I_

EN

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Bits

Name

Description

Table 15-9. MMC_CMDAT Bit Definitions (Sheet 1 of 2)

Physical Address

0x4110_0010

MMC_CMDAT Register

MultiMediaCard Controller

Bit

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

0

reserved

MMC

_

D

MA

_

E

N

IN

IT

BU

SY

S

T

RE

AM

_

B

L

O

C

K

W

R

IT

E

/RE

AD

DA

T

A

_

E

N

R

ESP

O

N

SE_

FO

RM

A

T

[1

:0

]

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

Bits

Name

Description

31:8

reserved

7

MMC_DMA_E

N

DMA Mode Enable

0 –

Program I/O mode

1 –

DMA mode

When DMA mode is used, this bit is a mask on RXFIFO_RD_REQ and TXFIFO_WR_REQ
interrupts.

6

INIT

80 Initialization Clocks

0 –

Do not precede command sequence with 80 clocks

1 –

Precede command sequence with 80 clocks

5

BUSY

Specifies whether a busy signal is expected after the current command.

This bit is for no data command/response transactions only.

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