ucb1200 NXP Semiconductors, ucb1200 Datasheet - Page 25

• Manufacturer Part Number: ucb1200
• Description: Advanced Modem/audio Analog Front-end
• Manufacturer: NXP Semiconductors

Philips Semiconductors
SERIAL INTERFACE BUS
The UCB1200 Serial Interface Bus (SIB) is compatible with industry standard serial ports and devices, and is designed
to connect directly to a system controller. The SIB protocol allows one or more slave devices to be connected to the
system controller. The data transfer is always synchronous and it is frame based. The SIB interface consists of four
signals: SIBDIN, SIBDOUT, SIBCLK and SIBSYNC.
Each SIB frame consists of at least 64 clock cycles. Typically 128 bits are used, divided into 2 sub frames of 64 bits each.
The first word (the bits 0 to 63) is read and/or written by the UCB1200, the remaining bits may be used for communication
between the system controller and another slave device. The SIBDOUT pin of the UCB1200 is tri-stated for the bit 64
and higher in the SIB frame to prevent bus conflicts with other slave devices. However when SIB_ZERO (control register
1) is set, the SIBDOUT pin is forced to zero from bit 64 onwards to prevent the SIBDOUT line from floating. This feature
is needed when the UCB1200 is the only slave device connected to the bus.
The UCB1200 always samples incoming data on the SIBDIN pin on the falling edge of SIBCLK and it outputs data on
the SIBDOUT pin on the rising edge of the SIBCLK. The start of a new SIB frame is indicated by a pulse on the SIBSYNC
line just before the start of this new SIB frame.
1998 Jul 22
Advanced modem/audio analog front-end
SIB MASTER
Fig.20 Typical connection between the UCB1200 and the system controller.
sibsync
sibdout
sibdin
sibclk
TO OTHER SIB SLAVES
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sibclk
sibsync
sibdin
sibdout
sibclk
sibsync
sibdin
sibdout
UCB1200
SIB SLAVE 2
Product specification
UCB1200