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Lucent Technologies Inc.
Lucent Technologies Inc.
35
Data Sheet
March 2000
ORCA OR3TP12 FPSC
Embedded Master/Target PCI Interface
PCI Bus Core Master Controller Detailed Description
(continued)
Table 10. Bit Definitions for Master Command/Address Phase
* Refer to PCI Specification 2.3 Section 3.1.
Master Write Operation
Command/Address Setup
In order to initiate a PCI Master write operation, the FPGA application must supply the Master command and PCI
start address in the specific order prescribed in Table 13 and Table 14, for quad- and dual-port mode respectively.
This data is transferred via bus
mwdata
(quad-port mode) or
datafmfpga
(
x
) (dual-port mode) and will be accepted
by the Master FIFO interface when
ma_fulln
is inactive and
m_ready
is active. The Master command word and
address must be accompanied by assertion of the enable
maenn
, with the command/address phase ending with
the assertion of
mwlastcycn
. The bit definitions of the Master command word is shown in Table 10. For Master
writes, the same burst length bit must be equal to zero.
All burst transactions or 64-bit agents (
pci_64bit
= 1) must start transactions on a 64-bit address boundary, which
requires address bit
ad2
= 0 for the PCI start address. If the write transaction needs to start on a odd 32-bit
address boundary (
ad2
= 1), the FPGA must send a padding data word to properly fill/align the Master write data
FIFO at the beginning of the data phase. This padding data word will be the first write data word transferred from
the FPGA application, and will have all of its byte enables deasserted. When the Master starts the PCI transaction
on a 32-bit bus, this padding data word will be dropped by the Master, with the resulting transaction starting on the
odd address (
ad2
= 1).
For single 32-bit transaction on 32-bit buses (
pci_64bit
= 0), the Master FIFO interface will perform the proper data
alignment. The FPGA application will transfer the PCI starting address, even or odd, during the command/address
phase and the valid 32-bit data word during the data phase.
Bits
Name
Description
Quad-Port
Dual-Port
Master Command Word (FPGA
→
PCI Core)
17
SPL
Master Read: Same Previous Burst
Length Indication (quad-port only)
Master Write: Must Be Zero
Dual-Address Indication
Not Used
Holding Register Selector:
0 = Select HR0
1 = Select HR1
Master Read: Byte Enables
Master Write: Not Used
PCI Command Code*
mwdata[17]
datafmfpgax[3]
16
DA
—
HR
mwdata[16]
mwdata[15:13]
mwdata[12]
datafmfpgax[2]
datafmfpga[31:29]
datafmfpga[28]
15:13
12
11:4
MRDBEN
mwdata[11:4]
datafmfpga[27:20]
3:0
Cmd
mwdata[3:0]
datafmfpga[19:16]
Master Read Burst Length Word (FPGA
→
PCI Core)
17:16
BL
Burst Length of 64-bit Words
15:0
BL
Burst Length of 64-bit Words
Master Address Word (FPGA
→
PCI Core)
17:16
—
Not Used
15:0
Adrs
Address
mwdata[17:16]
mwdata[15:0]
datafmfpgax[1:0]
datafmfpga[15:0]
mwdata[17:16]
mwdata[15:0]
datafmfpgax[1:0]
datafmfpga[31:0]