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Programmer’s Model
3-10
Copyright © 2006 ARM Limited. All rights reserved.
ARM DDI 0389B
3.3.5
SMC Direct Command Register at 0x1010
The write-only smc_direct_cmd Register passes commands to the external memory, and
controls the updating of the chip configuration registers with values held in the
set_opmode and set_cycles registers.
This register cannot be written to in either the Reset or Low-power state. Figure 3-10
shows the register bit assignments.
Figure 3-10 smc_direct_cmd Register bit assignments
Table 3-6 lists the register bit assignments.
VHWBFUH
$GGU
8QGHILQHG
FPGBW\SH
FKLSBVHOHFW
Table 3-6 smc_direct_cmd Register bit assignments
Bits
Name
Function
[31:26]
-
Reserved, undefined. Write as zero.
[25:23]
chip_select
Selects chip configuration register bank to update and enables chip mode register access depending
on cmd_type. The encoding is:
b000-b011 = chip selects 1-4 on interface 0
b100-b111 = reserved.
[22:21]
cmd_type
Determines the current command. The encoding is:
b00 = UpdateRegs and AHB command
b01 = ModeReg access
b10 = UpdateRegs
b11 = ModeReg and UpdateRegs.
[20]
set_cre
Maps to configuration register enable,
smc_cre
, output, when a ModeReg command is issued. The
encoding is:
b0 =
smc_cre
is LOW
b1 =
smc_cre
is HIGH when ModeReg write occurs.
[19:0]
addr
Bits mapped to external memory address bits [19:0] when command is ModeReg access.
Addr[19:16] are undefined.
Addr[15:0] matches
wdata[15:0]
when the commands are UpdateRegs and AHB command access.
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 ...