1. Functional Overview > Internal Switching Fabric (ISF)
30
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
1.5
Internal Switching Fabric (ISF)
The Internal Switching Fabric (ISF) is the crossbar switching matrix at the core of the Tsi578. It
transfers packets from ingress ports to egress ports and prioritizes traffic based on the RapidIO priority
associated with a packet and port congestion.
The ISF has the following features:
•
Full-duplex, non-blocking, crossbar-based switch fabric
•
10 Gbits/s fabric ports allow up to 10x internal speedup
•
Manages head-of-line blocking on each port
•
Cut-through and store-and-forward switching of variable-length packets
1.6
Internal Register Bus (AHB)
An internal multi-master Advanced High Performance Bus (AHB) allows any RapidIO port to
configure and maintain the entire device. When the Tsi578 receives a RapidIO maintenance packet
destined for itself, it translates the packet into register read or write request on the AHB.
The device registers can also be accessed through the JTAG interface or the I
2
C interface.
1.7
I
2
C Interface
The I
2
C Interface provides a master and slave serial interface that can be used for the following
purposes:
•
Initializing device registers from an EEPROM after reset
•
Reading and writing external devices on the I
2
C bus
•
Reading and writing Tsi578’s internal registers for management purposes by an external I
2
C
master
The I
2
C Interface has the following features:
•
Operates as a master or slave on the I
2
C bus
— Multi-master support
–
Arbitrates among multiple masters for ownership of the I
2
C bus
–
Automatically retries accesses if arbitration is lost
–
Provides timeout indication if the Tsi578 is unable to arbitrate for the I
2
C bus