2/24/2008 9T6WP
Preliminary Hardware Data Module
BCM7405
06/29/07
Functional Description
Bro a d c o m Co rp o r a ti o n
Document
7405-1HDM00-R
Peripherals Page 1-91
Soft Modem
•
High-performance V.92-capable software modem
•
Data, voice, and fax support
•
Minimal CPU overhead
•
Approximately 10% of the internal processor's cycles
•
Integrated SiLab System Side Device Module (Si3056)
-
Provides a two wire interface to a SiLab Si306X Line Side Device
-
Compatible only with SiLab Line Side Devices
-
Output to drive the modem speaker is provided using an additional signal
•
Optional 5-wire interface to an external DAA/Codec
Figure 1-33: Soft Modem Connections
PCI
The BCM7405 includes a version 2.3 PCI bus to allow the internal processor control of external peripherals that may be
attached to the PCI bus and to allow an external controller to access the peripherals and memory associated with the
BCM7405.
Software running on the internal MIPS32 processor can allow the BCM7405 to act as a South bridge. This allows an easier
migration path for external processors to access the peripheral devices (such as the USB controller). The PCI bus operates
at 33 MHz.
JTAG I
NTERFACE
The BCM7405 provides a test interface that implements the IEEE 1149.1a (JTAG) standard. The TAP controller implements
the required instructions; BYPASS, SAMPLE/PRELOAD, and EXTEST, as well as the optional instruction, IDCODE. The
user is referred to document IEEE 1149.1a-1993 for a complete description of the JTAG standard. This interface is also used
as the debug port to the MIPS.
BCM 7405
S oft M odem
Line S ide
Device
Si306X
RJ11
C onnector
2
B CM 7405
S oft M odem
CO DE C
S i3056
D AA
Si3010/
S i3018
RJ11
Connector
5
S
S
D
Integrated S iLab Si3056 System Side D evice
O ptional Interface to E xternal S ystem S ide Device
