EP80579 Datasheet, PDF (1765/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
48.4.4.4 Local Expansion Bus (LEB) Interface
Table 48-24. Expansion Bus Signals (Sheet 1 of 3)
Signal Name
EX_ALE
EX_ADDR[24:0]
EX_BE[1:0]#
EX_CLK
IO Type
LVTTL,3.3V
LVTTL,3.3V
LVTTL,3.3V
LVTTL,3.3V
Direction
Ball
Count
O
1
IO
25
IO
2
I
1
External
Pull-Up/
Down
[Ohms]
BSC/
XOR
Signal Description Normal/Alternate Mode
Expansion Bus Address Latch Enable/Advance/
LD#: Address latch enable signal for the
Expansion bus.
BSC
EXALE has pull-ups enabled when PLL_LOCK is
deasserted. These pull-ups are disabled when
PLL_LOCK is asserted and the EP80579 drives
the signal based upon grant. EXALE is driven by
the EP80579.
Expansion Bus Address: The 25-bit address bus
for the Expansion Bus.
EXADx has pull-ups enabled when PLL_LOCK is
deasserted to allow sampling of configuration
bits that select the address space size (see
strapping discussion).
These pull-ups are disabled when PLL_LOCK is
asserted and the EP80579 drives the signal
based upon grant. EXADx driven by the
EP80579.
BSC
Expansion Bus Memory Size Strap: This strap
selects the size of the memory space that the
Expansion Bus claims for its MMIO region. Bits
23, 22, and 21 encode the size.
The EP80579 interprets the value of the
EXAD[23:21] pins as follows:
000b - 0MB (i.e., Expansion bus disabled)
001b - 32MB
010b - 64MB
011b - 128MB
1XXb - 256MB
Note: Expansion Bus Memory Size should be
configured by strapping or by Pre-boot Firmware
to determine LEB_SIZE.
Expansion Bus Byte Enable: Byte enables for the
16-bit data bus in the Expansion Bus.
BSC
EXBEx has pull-ups enabled when PLL_LOCK is
deasserted. These pull-ups are disabled when
PLL_LOCK is asserted and the EP80579 drives
the signal based upon grant. EXBEx is driven by
EP80579.
BSC
These signals are active-low.
Expansion Bus Clock: EXCLK is always an input.
May be driven from a GPIO clock or
from an external clock source.
Maximum Frequency: 80MHz
Minimum Frequency: 33MHz
August 2009
Order Number: 320066-003US
Intel^® EP80579 Integrated Processor Product Line Datasheet
1765