TC1796
System Units (Vol. 1 of 2)
On-Chip System Buses and Bus Bridges
User’s Manual
6-19
V2.0, 2007-07
Buses, V2.0
6.4
System and Remote Peripheral Bus
The TC1796 has two on-chip FPI buses:
•
System Peripheral Bus (SPB)
– System bus for on-chip peripherals (except for SSCs and ADCs)
•
Remote Peripheral Bus (RPB)
– Mainly dedicated to DMA transactions of SSCs and ADCs with DMI memories
This section gives an overview of the two on-chip FPI buses. It describes its bus control
units, the bus characteristics, bus arbitration, scheduling, prioritizing, error conditions,
and debugging support. Both FPI buses have the same FPI-Bus functionality. If required,
implementation-specific differences are described.
6.4.1
Overview
The FPI buses interconnect the on-chip peripheral units with the TC1796 processor
subsystem.
gives an overview of the FPI Buses and the modules connected
to them.
The FPI Bus is designed to be quick to acquire by on-chip functional units, and quick to
transfer data. The low setup overhead of the FPI Bus access protocol guarantees fast
FPI Bus acquisition, which is required for time-critical applications.
The FPI Bus is designed to sustain high transfer rates. For example, a peak transfer rate
of up to 160 Mbyte/s can be achieved with the 32-bit data bus at 40 MHz bus clock.
Multiple data transfers per bus arbitration cycle allow the FPI Bus to operate at close to
its peak bandwidth.
Additional features of the FPI Bus include:
•
Optimized for high speed and high performance
•
Support of multiple bus masters
•
32-bit wide address and data buses
•
8-, 16-, and 32-bit data transfers
•
64-, 128-, and 256-bit block transfers
•
Central simple per-cycle arbitration
•
Slave-controlled wait state insertion
•
Support of atomic operations LDMST, ST.T and SWAP.W
•
Designed to minimize EMI and power consumption
The functional units of the TC1796 are connected to the FPI bus via FPI bus interfaces.
An FPI Bus interface act as bus agent, requesting bus transactions on behalf of their
functional unit, or responding to bus transaction requests.
There are two types of bus agents:
•
FPI Bus master agents can initiate FPI Bus transactions and can also act as slaves.
•
Slave agents can only react and respond to FPI Bus transaction requests in order to
read or write internal registers of slave modules as for example memories.