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UM10503
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© NXP B.V. 2015. All rights reserved.
User manual
Rev. 2.1 — 10 December 2015
597 of 1441
NXP Semiconductors
UM10503
Chapter 23: LPC43xx/LPC43Sxx External Memory Controller (EMC)
Lower priority requests are only serviced when no higher priority requests are active.
Same priority requests are serviced in turn (round-robin arbitration).
Static memories are mapped below 0x2000 0000. This memory area is addressed by the
M4 I/D-bus.
Dynamic memories are mapped above 0x1FFF FFFF. This memory area is addressed by
the M4 S-bus. When the M4 core is executing from SDRAM not much bandwidth is
remaining for lower priority bus masters (M0 and other bus masters except for the LCD
controller). Also see
Section 3.6 “AHB Multilayer matrix configuration”
23.5 Memory bank select
Eight independently-configurable memory chip selects are supported:
•
Pins EMC_CS3 to EMC_CS0 are used to select static memory devices.
•
Pins EMC_DYCS3 to EMC_DYCS0 are used to select dynamic memory devices.
Static memory chip select ranges are each 16 MB in size, while dynamic memory chip
selects cover a range of 256 MB each.
shows the address ranges of the chip
selects.
Fig 60. EMC block diagram (SRAM)
EMC_A[23:0]
EMC_WE
EMC_D[31:0] (write)
MEMORY
CONTROLLER
STATE
MACHINE
AHB SLAVE
REGISTER
INTERFACE
AHB SLAVE
MEMORY
INTERFACE
EMC
AH
B
EMC_CS[3:0]
EMC_OE
MA
TRIX
CLK_M4_EMC/
CLK_M4_EMC_DIV
CLK_M4_EMC/
CLK_M4_EMC_DIV
EMC_BLS[3:0]
EMC_D[31:0] (read)
DATAIN
FIFO
SRAM interface
Table 412. Memory bank selection
Chip select pin
Address range
Memory type
Size of range
EMC_CS0
0x1C00 0000 - 0x1CFF FFFF
Static
16 MB
EMC_CS1
0x1D00 0000 - 01DFF FFFF
Static
16 MB
EMC_CS2
0x1E00 0000 - 0x1EFF FFFF
Static
16 MB