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Intel® PXA255 Processor
Developer’s Manual
Memory Controller
6.6
Synchronous Static Memory Interface
The synchronous static memory interface supports SMROM and non-SDRAM-like Flash
memories. The synchronous static memory can be configured for any of the nCS[3:0] signals. Chip
Select 0 must be used for boot memory. Synchronous static memories in bank pairs 1/0 or 3/2 must
be set to the same timing.
If any of the nCS[3:0] banks are configured for Synchronous Static Memory via
SXCNFG[SXENx], the corresponding half-words of MSC0 (see
Section 6.7.3
) and MSC1, except
the data width in MSCx[RBWx], are ignored.
6.6.1
Synchronous Static Memory Configuration Register
(SXCNFG)
SXCNFG controls all synchronous static memory. SXCNFG[15:0] configures chip select signals 0
and 1. SXCNFG[31:16] configures chip select signals 2 and 3.
This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.
Figure 6-11. SDRAM 4-Beat Write / 4-Write Same Bank, Same Row
CL
tRCD
CL
tRCD
row
col
0
1
2
3
mask0 mask1
mask3
mask2
tRP = 2 clks
tRCD = 2 clks
tRAS = 2 clks
CL = 2 clks
col
4
5
6
7
mask4 mask5 mask6 mask7
0ns
25ns
50ns
75ns
100ns
SDCLK
nSDCS
MA[24:0]
nSDRAS
nSDCAS
nWE
DATA
DQM[3:0]
Summary of Contents for PXA255
Page 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Page 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Page 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Page 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Page 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Page 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Page 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Page 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Page 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
Page 600: ......