FEATURES

The PM8172 system controller is ideal for various designs of advanced set-top boxes, DVD players, game stations, and Internet terminal appliances. The PM8172 interfaces to PMC-Sierra’s RM5231A, RM7035C and RM7935 MIPS RISC processors.

CPU INTERFACE

• Connects to PMC-Sierra’s RM5231A, RM7035C, and RM7935 64-bit MIPS RISC microprocessors.

• Supports CPU bus frequencies up to 100 MHz.

SDRAM CONTROLLER

• 32-bit data bus interface.

• Supports two banks of SDRAM, up to 128 Mbytes in size.

• Provides a deep buffer for CPU to SDRAM burst transfers and for PCI to SDRAM burst transfers.

• Supports bus frequencies up to 100 MHz.

FLASH/ROM INTERFACE

• Supports Flash memory area up to 64 Mbytes, with 8-bit, 16-bit, and 32-bit data access capability.

• Supports a ROM area size up to 4 Mbytes, with 8-bit, 16-bit, and 32-bit data access capability.

• Supports a maximum of 12 chip-select signals.

• Shared with a 68K-like peripheral bus.

PERIPHERAL BUS CONTROLLER

• Provides a 68K-like bus interface.

• Does not require an external latch for addressing.

• Provides an 8-bit and 16-bit data bus interface.

• Shared with the Flash/ROM interface.

• Supports up to four DMA channels.

• Provides cycle posting to avoid performance hits from slower devices.

PCI BUS CONTROLLER

• Provides CPU to PCI buffers for burst

transfers.

• Provides a PCI arbiter that supports up

to five individual bus master devices.

• Supports 33 MHz bus frequency.

• Provides a 32-bit data bus interface.

INTERRUPT CONTROLLER

• Supports a maskable interrupt to the CPU and a non-maskable interrupt to the CPU for severe events.

• The priority order of interrupt request lines can be assigned by software.

• Module interrupts can be masked on/off independently by setting the corresponding mask registers.

DMA CONTROLLER

• Supports four channel requests for LPC or ECP DMA mode data transfers.

• Supports PCI bus master accessing to the SDRAM.

CHAINING DMA CONTROLLER

• Supports four independent software DMA channels for transferring data between SDRAM and PCI devices.

• Supports chaining and non-chaining modes.

• Supports rotating and fixed priority types. (Continue..)