Datasheet

141
SAM9261 [DATASHEET]
Atmel-6062O-ATARM-SAM9261-Datasheet_21-Jun-16
19.6.5.4 Multiplexing of CompactFlash Signals on EBI Pins
Table 19-8 and Table 19-9 illustrate the multiplexing of the CompactFlash logic signals with other EBI signals on
the EBI pins. The EBI pins in Table 19-8 are strictly dedicated to the CompactFlash interface as soon as the
EBI_CS4A and/or EBI_CS5A bit(s) of the EBI Chip Select Assignment Register is set. These pins must not be
used to drive any other memory devices.
The EBI pins in Table 19-9 remain shared between all memory areas when the corresponding CompactFlash
interface is enabled (CS4A = 1 and/or CS5A = 1).
19.6.5.5 Application Example
Figure 19-5 on page 142 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 Section 20. “Static Memory Controller (SMC)”.
Table 19-7. CompactFlash Mode Selection
Mode Base Address CFOE CFWE CFIOR CFIOW
Attribute Memory
Common Memory
NRD NWR0_NWE 1 1
I/O Mode 1 1 NRD NWR0_NWE
True IDE Mode 0 1 NRD NWR0_NWE
Table 19-8. Dedicated CompactFlash Interface Multiplexing
Pins
CompactFlash Signals EBI Signals
CS4A = 1 CS5A = 1 CS4A = 0 CS5A = 0
NCS4/CFCS0 CFCS0 NCS4
NCS5/CFCS1 CFCS1 NCS5
Table 19-9. 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