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UM10503
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User manual
Rev. 2.1 — 10 December 2015
611 of 1441
NXP Semiconductors
UM10503
Chapter 23: LPC43xx/LPC43Sxx External Memory Controller (EMC)
For example, for a static memory read/write transfer time of 16 µs, and a EMC_CCLK
frequency of 50 MHz, the following value must be programmed into this register:
(16 x 10
-6
x 50 x 10
6
) / 16 - 1 = 49
23.7.19 Dynamic Memory Configuration registers
These registers enable you to program the configuration information for the relevant
dynamic memory chip select. These registers are normally only modified during system
initialization. These registers are accessed with one wait state.
[1]
The SDRAM column and row width and number of banks are computed automatically from the address
mapping.
[2]
The buffers must be disabled during SDRAM initialization. The buffers must be enabled during normal
operation.
Table 433. Dynamic Memory Configuration registers (DYNAMICCONFIG[0:3], address
0x4000 5100 (DYNAMICCONFIG0) to 0x4000 5160 (DYNAMICCONFIG3)) bit
description
Bit
Symbol
Value Description
Reset
value
2:0
-
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-
4:3
MD
Memory device.
0
0x0
SDRAM (POR reset value).
0x1
Reserved.
0x2
Reserved.
0x3
Reserved.
6:5
-
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-
12:7
AM0
Address mapping.
See
0
13
-
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-
14
AM1
Address mapping
See
. 0 = reset value.
0
18:15 -
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-
19
B
Buffer enable.
0
Disabled. Buffer disabled for accesses to this chip select (POR
reset value).
1
Enabled. Buffer enabled for accesses to this chip select. After
configuration of the dynamic memory, the buffer must be
enabled for normal operation.
20
P
Write protect.
0
0
None. Writes not protected (POR reset value).
1
Protected. Writes protected.
31:21 -
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-