IDT88P8344 Integrated Device Technology, IDT88P8344 Datasheet - Page 23

• Manufacturer Part Number: IDT88P8344
• Description: Spi Exchange 4 X Spi-3 To Spi-4 Issue 1.0
• Manufacturer: Integrated Device Technology

datapaths shown are as follows:
All SPI-3 interfaces can operate independently in a PHY or Link mode. Refer
IDT88P8344 SPI EXCHANGE 4 x SPI-3 TO SPI-4
The following sections describe the datapaths through the device. The
- SPI-3A <-> SPI-4
- SPI-3B <-> SPI-4
- SPI-3C <-> SPI-4
- SPI-3D <-> SPI-4
- SPI-3A <-> SPI-3B
- SPI-3C <-> SPI-3D
- SPI-3A <-> microprocessor interface
- SPI-3B <-> microprocessor interface
- SPI-3C <-> microprocessor interface
- SPI-3D <-> microprocessor interface
- SPI-4 <-> microprocessor interface
Where <-> indicates a bidirectional data path.
The IDT88P8344 supports four SPI-3 interfaces and a single SPI-4 interface.
SPI-3C physical port
SPI-3D physical port
SPI-3B physical port
SPI-3A physical port
SPI-3 ingress
SPI-3 egress
from SPI-3
to SPI-3
Figure 11. Definition of data flows
SPI-4 insert
SPI-4 extract
23
SPI-4-3 path
SPI-3-4 path
to Figure 11, Definition of Data Flows for the main data flows in the device.
Independent logical data flows are transported over each of the physical ports.
Those logical flows are identified by logical port addresses on the physical port
and by a Link identification (LID) map in the core of the IDT88P8344.
DATA BUFFER ALLOCATION
has 128 KByte of on chip memory per SPI-3 port per direction – a total of 1MByte
of on-chip data memory.
256 byte segments. The segments are controlled by a packet fragment
processor. The user configures the maximum number of segments per LP to
allocate to a port and the number of segments allocated from the buffer segment
pool that will trigger the flow control mechanism. There is no limitation on the
reallocation of freed segments among logical ports, as would be present if the
memory had been allocated by a simple address mechanism.
Flexibility has been provided to the user for data buffer allocation. The device
The 128 KByte SPI-3 buffers (8 instantiations per device) are divided into
SPI-3 extract
SPI-3 insert
SPI-4 egress
SPI-4 ingress
to SPI-4
from SPI-4
INDUSTRIAL TEMPERATURE RANGE
6370 drwXA
SPI-4
physical
port
APRIL 10, 2006