Sdram Slave Arbiter; Ebi Bus Arbiter; Ahb Decoder; Ahb Slave - Cirrus Logic EP93 Series User Manual

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
(For additional information, see 17,
Address Range
0x800D_0000 - 0x800F_FFFF
0x800C_0000 - 0x800C_FFFF
0x800B_0000 - 0x800B_FFFF
0x800A_0000 - 0x800A_FFFF
0x8009_0000 - 0x8009_FFFF
0x8008_0000 - 0x8008_FFFF
0x8007_0000 - 0x8007_FFFF
0x8006_0000 - 0x8006_FFFF
0x8005_0000 - 0x8005_FFFF
0x8004_0000 - 0x8004_FFFF
0x8003_0000 - 0x8003_FFFF
0x8002_0000 - 0x8002_FFFF
0x8001_0000 - 0x8001_FFFF
0x8000_0000 - 0x8000_FFFF
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.
DS785UM1
ARM920T Core and Advanced High-Speed Bus (AHB)
Table 2-2.
"Reference Documents" on page

Table 2-2. AHB Peripheral Address Range

Register Width
-
32
32
32
32
32
-
32
-
-
32
32
32
32
Copyright 2007 Cirrus Logic
Peripheral Type Peripheral
- Reserved
AHB VIC2
AHB VIC1
AHB IDE
AHB Boot ROM physical address
AHB SRAM Controller/ PCMCIA
- Reserved
AHB SDRAM Controller
- Reserved
- Reserved
AHB Raster
AHB USB Host
AHB Ethernet MAC
AHB DMA
EP93xx User's Guide
P-3.
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