Embedded Solutions
Case study:
Development of Bluetooth serial driver
Customer:
One of the first companies to bring certified Bluetooth software
to the world
Technology:
Embedded; Bluetooth
The Customer
The customer is a leading software provider
of Bluetooth™ short-range wireless connectivity solutions,
one of the first companies to bring certified Bluetooth software
to the world, and a market leader in supplying Bluetooth software
and systems to semiconductor, consumer electronic manufactures,
and computing device OEMs.
The Challenge
The client had its Bluetooth stack deployed in
one of the most widely accepted PDA’s available at that
time. The Bluetooth applications were experiencing loss of data
while performing large data transfers over the Bluetooth interface.
The objective of the project was to develop a new serial device
driver to overcome this limitation. Tata Infotech had to design
a stream interface device driver for the BTUART port for Intel’s
PXA250 XScale processor. The driver was required to act like a
standard serial port driver, be accessible using commands such
as “open serial port”, support flow control and prevent
data loss at high speed. The driver was also required to have
an interface that is similar to the HCI UART interface of Bluetooth.
The Solution
Tata Infotech developed the serial driver for
the BTUART port of XScale processor. The driver was based on the
stream interface device driver model. Bluetooth Serial Driver
technology was employed to execute this process.
A two-layered architecture having MDD and PDD layers was developed.
DMA was used to transfer data from/to UART FIFO. The DMA buffer
chaining mechanism was used for this purpose. The driver supported
RTS/CTS flow control. The data transfer was tested by transferring
20MB files between two iPAQs and also by transferring 20MB files
between an iPAQ and Desktop PC with Bluetooth support.
The Benefits
-
Performance improvement of 15% was achieved
for transmission.
-
Improvement of 52% was achieved for reception
with the help of the driver.
-
The new driver eliminated the data loss
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