Figure 6-18 – Intel PXA255 User Manual

Page 232

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6-50

Intel® PXA255 Processor Developer’s Manual

Memory Controller

Figure 6-18. Eight-Beat Burst Read from 16-Bit Burst-of-Four ROM or Flash (MSC0[RDF] = 4,

MSC0[RDN] = 1, MSC0[RRR] = 0)

0

1

2

3

4

5

6

7

"00"

"0000"

tDOH

tDSOH

tCEH

tCES

RRR*2+1

RDF+1

RDN+1

RDF+2

RDN+1

RDF+2

tAS

tAS = Address Setup to nCS asserted = 1 clk_mem
tCES = nCS setup to nOE asserted = 0 ns
tCEH = nCS hold from nOE deasserted = 0 ns
tDSOH = MD setup to Address changing = 1.5 clk_mems plus
board routing delays
tDOH = MD hold from Address changing = 0 ns

* MSC0:RDF0 = 4, RDN0 = 1, RRR0 = 1

0ns

50ns

100ns

150ns

200ns

250ns

CLK_MEM

nCS[0]

MA[25:5]

MA[4:2]

MA[1:0]

nADV(nSDCAS)

nOE

nWE

RDnWR

MD[31:0]

DQM[3:0]

nCS[1]

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