Specifications

Embedded System Tools Guide (EDK 6.2i) www.xilinx.com 139
UG111 (v1.4) January 30, 2004 1-800-255-7778
VHDL Peripheral Definitions
R
x If more than one instance of a particular bus interface type is used on a core, a bus
identifier, <BI>, must be used in the signal identifier. The bus identifier can be as
simple as a single letter or as complex as a descriptive string with a trailing
underscore. The <BI> must be included in the port’s signal identifiers in the following
cases:
i The core has more than one slave PLB port.
i The core has more than one master PLB port.
i The core has more than one slave LMB port.
i The core has more than one slave DCR port.
i The core has more than one master DCR port.
i The core has more than one OPB port of any type (master, slave, or master/slave).
i The core has more than one port of any type and the choice of <Mn> or <Sln>
causes ambiguity in the signal names. For example, a core with both a master OPB
port and master PLB port and the same <Mn> string for both ports would require
a <BI> string to differentiate the ports since the address bus signal would be
ambiguous without <BI>.
For cores that have only a single bus interface (which is the case for most peripherals), the
use of the bus identifier string in the signal names is optional and the bus identifier will not
typically be included.
Global Ports
The names for the global ports of a peripheral (such as clock and reset signals) are
standardized. You can use any name for other global ports (such as the interrupt signal).
LMB - Clock and Reset
LMB_Clk
LMB_Rst
OPB - Clock and Reset
OPB_Clk
OPB_Rst
PLB - Clock and Reset
PLB_Clk
PLB_Rst
Slave DCR Ports
Slave DCR ports must follow these naming conventions:
x <Sln> is a meaningful name or acronym for the slave output. <Sln> must not contain
the string, “DCR” (upper or lower case or mixed case), so that slave outputs will not
be confused with bus outputs.
x <nDCR> is a meaningful name or acronym for the slave input. The last three
characters of <nDCR> must contain the string, “DCR” (upper or lower case or mixed
case).