96 www.xilinx.com PowerPC™ 405 Processor Block Reference Guide
1-800-255-7778 UG018 (v2.0) August 20, 2004
Chapter 2: Input/Output Interfaces
R
DSPLB 3:1 Core-to-PLB Line Write

The timing diagram in Figure2-27 shows a line w rite in a system with a PLB clock that

runs at one third the frequency of the PowerPC 405 clock.

The line write (wl1) is requested by the DCU in PLB cycle 2, which corresponds to

PowerPC 405 cycle 4. The BIU responds in the same cycle. The request is made in response

to a flush in PowerPC 405 cycles 1 and 2 (flush1). Data is sent from the DCU to the BIU in

PLB cycles 2 through 5 (PowerPC 405 cycles 4 through 15).

Figure 2-26: DSPLB 2:1 Core-to-PLB Line Read

Cycle 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
CPMC40 5CLK
UG018_30_101701
PPC405 Outputs:
C405PLBDCUREQUEST
C405PLBDCURNW
C405PLBDCUABUS[0:31] adr1
fill1
C405PLBDCUBE[0:7]
C405PLBDCUWRDBUS[0:63]
C405PLBDCUSIZE2
DCU
rl1
PLB/BIU Outputs:
PLBC405DCUADDRACK
PLBC405DCURDDBUS[0:63]
PLBC405DCURDWDADDR[1:3]
PLBC405DCURDDACK
PLBC405DCUWRDACK
PLBC405DCUBUSY
rl1
rl101 rl123 rl145 rl167
d101 d123 d145 d167
0246
PLBCLK