DESCRIPTION

The PM7364 FREEDM-32 Frame Engine and Datalink Manager device is a monolithic integrated circuit that implements HDLC processing, and PCI Bus memory management functions for a maximum of 128 bi-directional channels.

FEATURES

• Single-chip Peripheral Component Interconnect (PCI) Bus multi-channel HDLC controller.

• Supports up to 128 bi-directional HDLC channels assigned to a maximum of 32 channelised T1 or E1 links. The number of time-slots assigned to an HDLC channel is programmable from 1 to 24 (for T1) and from 1 to 31 (for E1).

• Supports up to 32 bi-directional HDLC channels each assigned to an unchannelised arbitrary rate link; subject to a maximum aggregate link clock rate of 64 MHz in each direction. Channels assigned to links 0 to 2 can have a clock rate of up to 45 MHz when SYSCLK is at or above 25 MHz and up to 52 MHz when SYSCLK is at 33 MHz. Channels assigned to links 3 to 31 can have a clock rate of up to 10 MHz.

• Supports up to two bi-directional HDLC channels each assigned to an unchannelised arbitrary rate link of up to 45 MHz when SYSCLK is at or above 25 MHz and up to 52 MHz when SYSCLK is at 33 MHz.

• Supports a mix of up to 32 channelised and unchannelised links; subject to the constraint of a maximum of 128 channels and a maximum aggregate link clock rate of 64 MHz in each direction.

• For each channel, the HDLC receiver performs flag sequence detection, bit de-stuffing, and frame check sequence validation. The receiver supports the validation of both CRC-CCITT and CRC-32 frame check sequences. The receiver also checks for packet abort sequences, octet aligned packet length and for minimum and maximum packet length.

• Alternatively, for each channel, the receiver supports a transparent mode where each octet is transferred transparently to host memory. For channelised links, the octets are aligned with the receive time-slots.

• For each channel, time-slots are selectable to be in 56 kbits/s format or 64 kbits/s clear channel format.

• For each channel, the HDLC transmitter performs flag sequence generation, bit stuffing, and, optionally, frame check sequence generation. The transmitter supports the generation of both CRC-CCITT and CRC-32 frame check sequences. The transmitter also aborts packets under the direction of the host or automatically when the channel underflows.

• Supports two levels of non-preemptive packet priority on each transmit channel. Low priority packets will not begin transmission until all high priority packets are transmitted.

• Alternatively, for each channel, the transmitter supports a transparent mode where each octet is inserted transparently from host memory. For channelised links, the octets are aligned with the transmit time-slots.

• Directly supports a 32-bit, 33 MHz PCI 2.1 interface for configuration, monitoring and transfer of packet data, with an on-chip DMA controller with scatter/gather capabilities.

• Provides 8 kbytes of on-chip memory for partial packet buffering in each direction. This memory can be configured to support a variety of different channel configurations from a single channel with 8 kbytes of buffering to 128 channels, each with a minimum of 48 bytes of buffering.

• Supports PCI burst sizes of up to 128 bytes for transfers of packet data.

• Pin compatible with PM7366 (FREEDM-8) device.

• Provides a standard 5 signal P1149.1 JTAG test port for boundary scan board test purposes.

• Supports 3.3 and 5 Volt PCI signaling environments.

• Low power CMOS technology.

• 256 pin enhanced ball grid array (SBGA) package (27 mm X 27 mm).

APPLICATIONS

• IETF PPP interfaces for routers

• Frame Relay interfaces for ATM or Frame Relay switches and multiplexors

• FUNI or Frame Relay service inter-working interfaces for ATM switches and multiplexors.

• D-channel processing in ISDN terminals and switches.

• Internet/Intranet access equipment.

• Packet-based DSLAM equipment.