Figure 2-3. main data paths -8 – Cirrus Logic EP93xx User Manual
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DS785UM1
Copyright 2007 Cirrus Logic
ARM920T Core and Advanced High-Speed Bus (AHB)
EP93xx User’s Guide
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Figure 2-3. Main Data Paths
Before an AMBA-to-AHB transfer can commence, the bus master must be granted access to
the bus. This process is started by the master asserting a request signal to the Arbiter. The
Arbiter then indicates when the master will be granted use of the bus. A granted bus master
starts an AMBA-to-AHB transfer by driving the address and control signals. These signals
provide information on the address, direction and width of the transfer, as well as indicating
whether the transfer is part of a burst.
Two different forms of burst transfers are allowed:
•
Incrementing bursts, which do not wrap at address boundaries
•
Wrapping bursts, which wrap at particular address boundaries.
SDRAM
Controller
Static
Memory/
E
B
I
GPIOs
PWM
SPI
I2S
DMA
AHB/APB
bridge
AHB
APB
Clock & State
Boot ROM
USB
Host
Touchscreen
IrDA
RTC
Control
PLL1
PLL2
Test
Support
Watchdog
VIC2
VIC1
AC97
IDE
Ethernet
Timers
UARTs
8x8 Key Mtx
ARM920T
Maverick
18 Bit Raster
LCD I/F
Crunch
PCMCIA