UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
89 of 362
NXP Semiconductors
UM10208
Chapter 8: LPC2800 EMC
8.
Reset
The EMC receives two reset signals. One is called nPOR, and is asserted when chip
power is applied. nPOR affects all of the register bits in the EMC. The other signal is
called HRESETn, and is driven from the external Reset pin, the Watchdog Timer, and the
software reset facility of the CGU. HRESETn affects fewer register bits, so that refresh
activity and the contents of external dynamic memory are not lost during a "softer" reset.
9.
Pin description
shows the interface and control signal pins for the EMC on the LPC288x.
Table 75.
Memory bank selection
Chip select pin
Address range
Memory type
Size of range
STCS0
0x2000 0000 - 0x201F FFFF and
0x4000 0000 - 0x401F FFFF
Static
2 MB
STCS1
0x2400 0000 - 0x241F FFFF and
0x4400 0000 - 0x441F FFFF
Static
2 MB
STCS2
0x2800 0000 - 0x281F FFFF and
0x4800 0000 - 0x481F FFFF
Static
2 MB
DYCS
0x3000 0000 - 0x33FF FFFF and
0x5000 0000 - 0x53FF FFFF
Dynamic
64 MB
Table 76.
Pad interface and control signal descriptions
Name
Type
Value on
POR reset
Value during
self-refresh
Description
A[20:0]
Output Low
Depends on
static memory
accesses
External memory address output. Used for both
static and SDRAM devices. SDRAM memories
only use A[14:0].
D[15:0]
Input/
Output
Data
outputs =
Low
Depends on
static memory
accesses
External memory data lines. These are inputs
when data is read from external memory and
outputs when data is written to external
memory.
OE
Output High
Depends on
static memory
accesses
Low active output enable for static memory
devices.
BLS[1:0]
Output High
Depends on
static memory
accesses
Low active byte lane selects. Used for static
memory devices.
WE
Output High
Depends on
static memory
accesses
Low active write enable. Used for SDRAM and
static memories.
STCS[2:0]
Output High
Depends on
static memory
accesses
Static memory chip selects. Default active
LOW.
DYCS
Output High
High
SDRAM chip select.
CAS
Output High
High
Column address strobe. Used for SDRAM
devices.
RAS
Output High
High
Row address strobe. Used for SDRAM devices.