Sundance SMT338 - Manual (Page 8)

Version 1.5 Page 8 of 19 SMT338 User Manual
1.2. Sundance Digital Bus (SDB)
The four 40-way miniature IDC connectors’ primary function is to provide bi-directional 16-
bit data paths between TIMs with data transfer rates over 200 Mbytes/s.
Data rates of 200 Mbytes/second through a connector have been achieved using a
ground interlaced signal cable.
Each high speed Sundance Digital Bus (SDB) Interface can transfer 16-bit data, to
and from the TIM, at such a transfer rate.
400 Mbytes/Second Data rates can be reached using in parallel 2 (SDB) Interfaces to
send a 32-bit data every clock cycle at 100 MHz
The SDB Interface packs the 16-bit data transmitted into a 32-bit Word and stacks
them into a FIFO ready to be used.
The transmission can be fully bi-directional.
Many of Sundance TIM modules are being designed with this interface.
A SDB Interface is available from Sundance Multiprocessor Technology IP Centre.
Alternatively, the Sundance Digital Bus links can be extended to external
interconnection by connecting them to the SMT373 mezzanine card.
With this card, TTL signals are converted to Low-Voltage Differential signals and can
connect two systems several meters apart.
It provides two bi-directional 20-bit channels that can transfer up to 2 Gbytes/s through forty
SN65LVDM176 transceivers. Each channel provides 16 bit of data, a clock and a clock-
enable signal with their direction controlled by one signal. Two other signals can be used for
the bus arbitration in a bi-directional application. The direction of each of them can be
controlled independently.
All the signals controlling the direction are connected to the SMT338 FPGA through the
connectors and so can be controlled by software.
1.3. SMT338-DSP Communication channels
The global bus or Comm-Port 0,1,2,34,5 or 6 are communication channels of the SMT338
used to interfaced to T.I.’s DSP processors.
The ‘C4x Protocol defines Byte-wide links which can theoretically transmit at
20Mbytes/second asynchronously between TIMs.
The Global Bus is only available when the SMT338 is connected onto the SMT350PB
motherboard.
The SMT350PB provides a non-blocking global bus interconnection between any source TIM
site and any other destination TIM site. It provides a sustainable throughput of 50 Mbytes/s