Data Sheet
June 2001
DSP16410B Digital Signal Processor
Agere Systems Inc.
Agere Systems—Proprietary
Use pursuant to Company instructions
153
4 Hardware Architecture
(continued)
4.16 Serial Interface Unit (SIU)
(continued)
4.16.1 Hardware Interface
The system interface to the SIU consists of seven pins, described in
Table 88
.
Table 88. SIU External Interface
Pin
Type
SID
I
SIU Input
Name
Description
Data
SIU Input
Bit Clock
The SIU latches data from SID into its input shift register. By default, the SIU latches data from
SID on each falling edge of the input bit clock.
By default, SICK is configured as an input (passive) that provides the serial input bit clock. Alter-
natively, the SIU can generate the input bit clock internally and can drive this clock onto the SICK
output (active).
SIFS specifies the beginning of a new input frame. By default, SIFS is active-high and is config-
ured as an input (passive). Alternatively, the SIU can generate the input frame sync internally
and can drive this sync onto the SIFS output (active). To support a 2x ST-Bus interface, SIFS can
be configured as an input that synchronizes the internally generated (active) input and output bit
clocks.
The SIU drives data onto SOD from its output shift register. By default, the SIU drives data onto
SOD on each rising edge of the output bit clock. The SIU 3-states SOD during inactive or
masked channel periods.
By default, SOCK is configured as an input (passive) that provides the serial output bit clock.
Alternatively, the SIU can generate the output bit clock internally and can drive this clock onto the
SOCK output (active).
SOFS specifies the beginning of a new output frame. By default, SOFS is active-high and is con-
figured as an input (passive). Alternatively, the SIU can generate the output frame sync internally
and can drive this sync onto the SOFS output (active).
SCK is an input that provides an external clock source for generating the active mode input and
output bit clocks and frame syncs.
SICK
I/O/Z
SIFS
I/O/Z
SIU Input
Frame Sync
SOD
O/Z
SIU Output
Data
SOCK I/O/Z
SIU Output
Bit Clock
SOFS I/O/Z
SIU Output
Frame Sync
SCK
I
SIU External
Clock Source
The name of the pins has a 0 suffix for SIU0 and a 1 suffix for SIU1.