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Programmer’s Model
ARM DDI 0389B
Copyright © 2006 ARM Limited. All rights reserved.
3-13
Table 3-8 lists the register bit assignments.
Table 3-8 smc_set_opmode Register bit assignments
Bits
Name
Function
[31:16]
-
Reserved, undefined, write as zero.
[15:13]
set_burst_align
Holding register for value to be written to the specific SRAM chip opmode Register
burst_align field.
These bits determine whether memory bursts are split on memory burst boundaries:
000 = bursts can cross any address boundary
001 = burst split on memory burst boundary, that is, 32 beats for continuous
010 = burst split on 64 beat boundary
011 = burst split on 128 beat boundary
100 = burst split on 256 beat boundary
others = reserved.
Note
For asynchronous transfers:
•
the AHB MC always aligns read bursts to the memory burst boundary, when
set_rd_sync = 0
•
the AHB MC always aligns write bursts to the memory burst boundary, when
set_wr_sync = 0.
[12]
set_bls
Holding register for value to be written to the specific SRAM chip smc_opmode Register
byte lane strobe
(bls) field. This bit affects the assertion of the byte-lane strobe outputs.
b0 = bls timing equals chip select timing. This is the default setting.
b1 = bls timing equals
smc_we_n_0
timing. This setting is used for eight bit wide memories
that have no
smc_bls_n_0[3:0]
inputs. In this case the
smc_bls_n_0[3:0]
output of the
memory controller is connected to the
smc_we_n_0
memory input.
[11]
set_adv
Holding register for the value to be written to the specific SRAM chip smc_opmode Register
address valid (
adv) field. The memory uses the address advance signal
smc_adv_n_0
when
set.
[10]
set_baa
Holding register for value to be written to the specific SRAM chip smc_opmode Register
Burst Address Advance
(baa) field. The memory uses the
smc_baa_n_0
signal when set.
Содержание PrimeCell PL241
Страница 20: ...Introduction 1 6 Copyright 2006 ARM Limited All rights reserved ARM DDI 0389B ...
Страница 60: ...Functional Overview 2 40 Copyright 2006 ARM Limited All rights reserved ARM DDI 0389B ...
Страница 94: ...Device Driver Requirements 5 6 Copyright 2006 ARM Limited All rights reserved ARM DDI 0389B ...
Страница 104: ...Signal Descriptions A 10 Copyright 2006 ARM Limited All rights reserved ARM DDI 0389B ...
Страница 110: ...Glossary Glossary 6 Copyright 2006 ARM Limited All rights reserved ARM DDI 0389B ...