PSB7238 SIEMENS [Siemens Semiconductor Group], PSB7238 Datasheet - Page 21

• Manufacturer Part Number: PSB7238
• Description: Joint Audio Decoder-Encoder - Multimode
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

2
2.1
Figure 6 shows a sketch of the PSB 7238 architecture with its most important functional
modules.
Figure 6
The audio processing of the PSB 7238 is based on a 16-bit fixed point DSP core, SPCF
(Signal Processor Core Fast).
The Clock Generator is responsible for generating the internal clocks for the SPCF. A
Baud Rate Generator provides an output clock of programmable rate.
The Parallel Host Interface is used to control the circuit through an associated host via
interrupt handshake procedures. Alternatively, the circuit can be controlled via the serial
audio interface, thus enabling standalone applications to be implemented.
Communication between the host, if used, and the DSP is interrupt supported, via a
full-duplex 256-byte on-chip Communication Memory Mailbox.
Semiconductor Group
SC LK
SR
ST
R FS
TFS
General Architecture and Functions
Architecture
Serial
Audio
Con fi g/ Cont rol
I/F
Regis ters
Ti m ers
Audio
C A(0 :15 )
SIO
8 K W dat a
Rec 1
X-RO M
External Memor y Interface
32 KW pro gram
A D(0 :7)
Trm 1
Parallel Ho st Interface
C D(0 :15)
ROM
Rec 2
A(0 :3)
Trm 2
2 K W dat a
X-RA M
RD#
C RD#
WR#
256 byt e
CWR#
Ma ilb ox
21
256 b y te
C S#
Mailbox
1 K W dat a
X -RA M
C PS#
A L E
C DS#
C or e
General Architecture and Functions
INTR#
D SP
HDLC 1
1 K W d ata
IN T#
Y-RA M
HDLC 2
Re se t
Mo n, C/I
Control
GPIO
clo ck
BRG
gen/
PCM
PLL
IOM/
I/F
EA#
Data Sheet 1998-07-01
D D
D U
D CL
FSC
C M1
C L KO
XTA L1
XTA L2
GP( 0:3 )
PSB 7238