SPWS006 - NOVEMBER 1991
The TMS380SRA source-routing accelerator (SRA) device provides the hardware for direct recognition and parsing of the source-routing field in a token-ring frame. The TMS380SRA is designed to interface directly to the TMS380Cx6. The TMS380SRA searches the received frame for frames that need to be forwarded to the adjacent ring by examining the source-routing field. If a frame is to be forwarded, the frame is copied by the adapter and transferred to the attached system through the system interface of the TMS380Cx6. A second adapter with the TMS380SRA can also be included in the attached system (thus forming a bridge) to provide an identical function for the second ring. Transfer of data between the two rings (bridging) occurs under attached system-software control.
A block diagram of the TMS380SRA is shown in Figure 1. The internal registers fall into two categories: registers that can be set by the host software for the specific bridge parameters for this adapter, and dynamic registers that are loaded with the received frames-routing information as read from the adapter bus transfer. The routing information is compared to the specified bridge parameters, which determines the value to be placed on the XMATCH and XFAIL pins. The memory-interface (MIF) address output during memory cycles is shown in Table 1. Status information is provided on the MADH0-MADH7 signals in the second quarter of the memory cycle (shaded area). MADH6 and MADH7 are the bits that can be used by an EACO device. The information provided in these bits during the second quarter of the memory cycle can be decoded as follows:
The decode of the rest of the status information is shown in Table 2 and Table 3.
The TMS380SRA is available in a 44-lead plastic chip-carrier package (FN suffix) and is characterized for operation from 0°C to 70°C (L suffix). The electrostatic-discharge protection of the TMS380SRA is rated at 500 V human-body model (HBM).
View more information about generic part numbers:TMS380SRA
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