Cirrus Logic EP93xx - Manual (Page 49)

DS785UM1 2-11
Copyright 2007 Cirrus Logic
ARM920T Core and Advanced High-Speed Bus (AHB)
EP93xx User’s Guide
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2.2.8.2 SDRAM Slave Arbiter
The SDRAM Slave Arbiter prioritizes between accesses from the AHB bus and the Raster
DMA bus. If an access request from the AHB arrives at the same time as an access request
from the Raster DMA, the Raster DMA will be given access while the AHB request is queued.
2.2.8.3 EBI Bus Arbiter
The EBI Bus Arbiter is used to arbitrate between accesses from the SDRAM controller and
the Static Memory controller, where priority is given to accesses from the SDRAM controller.
2.3 AHB Decoder
The AHB Decoder contains the device memory map for all of the AHB masters/slaves and for
the APB bridge. When a particular address range is selected, the appropriate signal is
generated as defined in
Table 2-2 .
(For additional information, see 17 , “Reference Documents” on page P-3 .
Note: Due to decoding optimization, the AHB peripheral registers are aliased throughout each
peripherals register bank. Do not attempt to access an unspecified register within the
bank.
2.3.1 AHB Slave
An AHB Slave responds to transfers initiated by bus masters. The slave uses signals from
the decoder to determine when it should respond to a bus transfer. All other signals required
for the transfer, such as the address and control information, are generated by the bus
master.
Table 2-2. AHB Peripheral Address Range
Address Range Register Width Peripheral Type Peripheral
0x800D_0000 - 0x800F_FFFF - - Reserved
0x800C_0000 - 0x800C_FFFF 32 AHB VIC2
0x800B_0000 - 0x800B_FFFF 32 AHB VIC1
0x800A_0000 - 0x800A_FFFF 32 AHB IDE
0x8009_0000 - 0x8009_FFFF 32 AHB Boot ROM physical address
0x8008_0000 - 0x8008_FFFF 32 AHB SRAM Controller/ PCMCIA
0x8007_0000 - 0x8007_FFFF - - Reserved
0x8006_0000 - 0x8006_FFFF 32 AHB SDRAM Controller
0x8005_0000 - 0x8005_FFFF - - Reserved
0x8004_0000 - 0x8004_FFFF - - Reserved
0x8003_0000 - 0x8003_FFFF 32 AHB Raster
0x8002_0000 - 0x8002_FFFF 32 AHB USB Host
0x8001_0000 - 0x8001_FFFF 32 AHB Ethernet MAC
0x8000_0000 - 0x8000_FFFF 32 AHB DMA