Revision 1.25 – December 18, 2006
440EP – PPC440EP Embedded Processor
Internal Buses
Data Sheet
The PowerPC 440EP features five standard on-chip buses: two Processor Local Buses (PLBs), two On-Chip
Peripheral Buses (OPBs), and the Device Control Register Bus (DCR). The high performance, high bandwidth
cores such as the PowerPC 440 processor core, the DDR SDRAM memory controller, and the PCI bridge connect
to the PLBs. The primary OPB hosts lower data rate peripherals. The secondary OPB is dedicated to USB 2.0 and
DMA. The daisy-chained DCR provides a lower bandwidth path for passing status and control information between
the processor core and the other on-chip cores.
Features include:
• PLB 128 (PLB4)
– 128-bit implementation of the PLB architecture
– Separate and simultaneous read and write data paths
– 36-bit address
– Simultaneous control, address, and data phases
– Four levels of pipelining
– Byte-enable capability supporting unaligned transfers
– 32- and 64-byte burst transfers
– 133MHz, maximum 4.25GB/s (simultaneous read and write)
– Processor:bus clock ratios of N:1 and N:2
• PLB 64 (PLB3)
– 64-bit implementation of the PLB architecture
– 32-bit address
– 133MHz (1:1 ratio with PLB 128), maximum 1.1GB/s (no simultaneous read and write)
• OPB (2)
– 32-bit data path
– 32-bit address
– 66.66MHz
• DCR
– 32-bit data path
– 10-bit address
AMCC Proprietary
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AMCC [ APPLIED MICRO CIRCUITS CORPORATION ]
