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UM10503
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© NXP B.V. 2015. All rights reserved.
User manual
Rev. 2.1 — 10 December 2015
614 of 1441
NXP Semiconductors
UM10503
Chapter 23: LPC43xx/LPC43Sxx External Memory Controller (EMC)
23.7.21 Static Memory Configuration registers
These registers configure the static memory configuration. It is recommended that these
registers are modified during system initialization, or when there are no current or
outstanding transactions. This can be ensured by waiting until the EMC is idle, and then
entering low-power, or disabled mode. These registers are accessed with one wait state.
Table 435. Dynamic Memory RASCAS Delay registers (DYNAMICRASCAS[0:3], address
0x4000 5104 (DYNAMICRASCAS0) to 0x4000 5164 (DYNAMICRASCAS3)) bit
description
Bit
Symbol
Value Description
Reset
value
1:0
RAS
RAS latency (active to read/write delay).
11
0x0
Reserved.
0x1
One EMC_CCLK cycle.
0x2
Two EMC_CCLK cycles.
0x3
Three EMC_CCLK cycles (POR reset value).
7:2
-
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-
9:8
CAS
CAS latency.
11
0x0
Reserved.
0x1
One EMC_CCLK cycle.
0x2
Two EMC_CCLK cycles.
0x3
Three EMC_CCLK cycles (POR reset value).
31:10 -
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-
Table 436. Static Memory Configuration registers (STATICCONFIG[0:3], address 0x4000 5200
(STATICCONFIG0) to 0x4000 5260 (STATICCONFIG3)) bit description
Bit
Symbol
Value Description
Reset
value
1:0
MW
Memory width.
0
0x0
8 bit (POR reset value).
0x1
16 bit.
0x2
32 bit.
0x3
Reserved.
2
-
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-
3
PM
Page mode.
In page mode the EMC can burst up to four external accesses.
Therefore devices with asynchronous page mode burst four or
higher devices are supported. Asynchronous page mode burst
two devices are not supported and must be accessed normally.
0
0
Disabled. (POR reset value.)
1
Enabled. Async page mode enabled (page length four).