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PEB 20321
PEF 20321
Microprocessor Bus Interface
Data Sheet
135
2001-02-14
5
Microprocessor Bus Interface
The MUNICH32X may be configured either for 33 MHz/32-bit PCI operation, or for a
33 MHz/32-bit De-multiplexed bus. The MUNICH32X
’
s DEMUX input pin is used to
select the desired configuration (
‘
0
’
= PCI,
‘
1
’
= DEMUX).
The MUNICH32X provides identical DMA controller capability for both interfaces.
When in the PCI configuration, connection to other peripherals (e.g., ISDN transceivers,
FALC54, ISAC-S or ESCC2) may be made through the MUNICH32X
’
s Local Bus
Interface (LBI).
5.1
PCI Bus Interface
In this configuration, the MUNICH32X interfaces directly
to a 33 MHz/32-bit PCI bus.
During run-time, the MUNICH32X operates mostly as a PCI Master; it may be accessed
by the host processor as a PCI Slave. During device configuration, the MUNICH32X
operates only as a slave device; memory transactions are used to configure the device.
The MUNICH32X is compliant with the PCI specification 2.1 at up to 33 MHz.
In addition, the MUNICH32X supports little/big endian byte swapping for the data
section, and unaligned-byte accesses for transmit data.
5.1.1
Memory accesses as a PCI Master:
The MUNICH32X supports both the PCI Memory
Write and PCI Memory Read commands. For the PCI Memory Write command, it writes
to an agent mapped in the memory access space, while for the PCI Read command, it
reads from an agent mapped in the memory address space.
I/O accesses as a PCI Master:
The MUNICH32X does not support the PCI I/O Write
nor PCI I/O Read commands.
Memory accesses as a PCI Slave:
The MUNICH32X supports both the PCI Memory
Write and PCI Memory Read commands. For the PCI Memory Write command, the
MUNICH32X is written to as an agent mapped in the memory address space, while for
the PCI Memory Read command, the MUNICH32X is read from as an agent mapped in
the memory address space.
I/O accesses as a PCI Slave:
The MUNICH32X does not support the PCI I/O Write nor
PCI I/O Read commands.
Burst Capability:
Read/write descriptors: up to 3 DWORDs, read/write data for
MUNICH32 core: 1 DWORD, read/write data for LBI interface: up to 8 DWORDs.
PCI Transactions Supported
5.1.2
The PCI Configuration Space Registers of the MUNICH32X are listed
Table 12
.
PCI Configuration Space Registers