Illust – Rainbow Electronics AT91CAP9S250A User Manual

Page 154

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154

6264A–CAP–21-May-07

AT91CAP9S500A/AT91CAP9S250A

21.5.8.5

Application Example

Figure 21-4 on page 154

illustrates an example of a CompactFlash application. CFCS0 and

CFRNW signals are not directly connected to the CompactFlash slot 0, but do control the
direction and the output enable of the buffers between the EBI and the CompactFlash Device.
The timing of the CFCS0 signal is identical to the NCS4 signal. Moreover, the CFRNW signal
remains valid throughout the transfer, as does the address bus. The CompactFlash _WAIT
signal is connected to the NWAIT input of the Static Memory Controller. For details on these
waveforms and timings, refer to the section “Static Memory Controller (SMC)”.

Figure 21-4. CompactFlash Application Example

Table 21-8.

Shared CompactFlash Interface Multiplexing

Pins

Access to CompactFlash Device

Access to Other EBI Devices

CompactFlash Signals

EBI Signals

NRD/CFOE

CFOE

NRD

NWR0/NWE/CFWE

CFWE

NWR0/NWE

NWR1/NBS1/CFIOR

CFIOR

NWR1/NBS1

NWR3/NBS3/CFIOW

CFIOW

NWR3/NBS3

A25/CFRNW

CFRNW

A25

CompactFlash Connector

EBI

D[15:0]

/OE

DIR

CD1

CD2

/OE

D[15:0]

A25/CFRNW

NCS4/CFCS0

CD (PIO)

A[10:0]

A22/REG

NOE/CFOE

A[10:0]

REG

OE

WE

IORD

IOWR

CE1

CE2

NWE/CFWE

NWR1/CFIOR

NWR3/CFIOW

CFCE1

CFCE2

WAIT

NWAIT

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