Xilinx UG018 ISOCM Input Ports, Attributes

154 www.xilinx.com PowerPC™ 405 Processor Block Reference Guide
1-800-255-7778 UG018 (v2.0) August 20, 2004
Chapter 3: PowerPC 405 OCM Controller
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ISOCM Input Ports, Attributes
Attributes are inputs to the OCM controller, from the FPGA fabric, that must be connected
to initialize control registers at FPGA power-up, or following a PPC405 reset. The ISINIT
and ISFILL registers cannot be initialized in this manner. These registers are initialized
only through “move to DCR” (mtdcr) instructions. Application software can also mod ify
the contents of the ISARC and ISCNTL registers using mtdcr and mfdcr instructions.
Tabl e 3-7 describes the ISOCM attributes.
Table 3-7: ISOCM Attributes
Attribute Direction Description
ISCNTLVALUE[0:7] Input This input bus is loaded into th e ISCNTL register at FPGA power-up.
The value is used to configure the operational characteristics of the
ISOCM controller. See Figure3 -13, page 164, and Figure 3-14, page 165,
for register bit definitions.
ISARCVALUE[0:7] Input This input bus is loaded into the ISAR C register at FPGA power up. It
defines the 16 MB memory space location for the instruction-side
memory interface. See Figure 3-13, page 164, and Figure 3-14, page 165,
for register bit definitions.
TIEISOCMDCRADDR[0:7]
Virtex-II Pro Only
Input This input bus defines the eight most significant bits of the ten-bit DCR
address bus for the ISOCM DCR control registers. The two least
significant bits are predefined in the ISOCM controller.
For example, if TIEISOCMDCRADDR[0:7] = 00_0010_11, then:
xThe DCR address of ISINIT register = 00_0010_1100 = 0x02C
xThe DCR address of ISFILL = 00_0010_1101 = 0x02D
xThe DCR address of ISARC = 00_0010_1110 = 0x02E
xThe DCR address of ISCNTL = 00_0010_1111 = 0x02F
TIEDCRADDR[0:5]
Virtex -4 On ly
Input This input bus defines the six most significant bits of the 10-bit DCR
address space for DCR control and status registersa for the OCM, APUb,
and EMACc sub modules.
For example, if TIEDCRADDR = 00_0001 then:
xThe DCR address of the ISINIT register = 00_0001_0000 =
0x010
xThe DCR address of the ISFILL register = 00_0001_0001 =
0x011
xThe DCR address of the ISARC register = 00_0001_0010 =
0x012
xThe DCR address of the ISCNTL register = 00_0001_0011 =
0x013
a. Refer to the “Device-Control Register Interfaces” section in Chapter 2 for more information.
b. Refer to Chapter 4, “PowerPC 405 APU Controller” for more information.
c. Refer to the “Virtex-4 Ethernet Media Access Controller” manual for more information.