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TSS901E

Rev. C – 24-Aug-01

Operation Modes

According to the different protocol formats expected for the operation of the TSS901E,

two major operation modes are implemented into the TSS901E. The operation modes

are chosen individually for each link channel by setting the respective configuration reg-

isters via the HOCI or via the link.

•

Transparent Mode (default after reset): This mode allows complete transparent

data transfer between two nodes without performing any interpretation of the

databytes and without generating any acknowledges. It is completely up to the host

CPU to interpret the received data and to generate acknowledges if required.

The TSS901E accepts EOP1 and EOP2 control tokens as packet delimiters and

generates autonomously EOP1/EOP2 (as configured) markers after each end of a

transmission packet.

This mode also includes as a special submode:

–

Wormhole routing: This mode allows hardware routing of packets by the

TSS901E.

•

Simple Interprocessor Communication (SIC) Protocol Mode: This mode executes

the simple interprocessor communication protocol as described in the protocol

TSS901E:

–

interpretation of the first 4 data tokens as the header bytes of the protocol

–

autonomous execution of the simple control commands as described in the

–

autonomous acknowledgement of received packets if configured

In transmit direction no interpretation of the data is performed. This means that for

transmit packets, the four header bytes must be generated by the host CPU and

must be available as the first data read from the communication memory.

EOP1/EOP2 control tokens are automatically inserted by the TSS901E when one

configured transfer from the communication memory has finished.

1.

Rastetter P. et.al., Simple Interprocessor Communication Protocol Specification, DIP-

SAPII-DAS-31-01, Issue 3, 08.10.96, also available on the same web site as the users

guide.