peb20560 Infineon Technologies Corporation, peb20560 Datasheet - Page 158

• Manufacturer Part Number: peb20560
• Description: Dsp Oriented Pbx Controller Doc
• Manufacturer: Infineon Technologies Corporation

Semiconductor Group
Stream 0/1
Bits 7:5
Bits 15:8
The PEDIU gets only the 8 lsbs of the address (DXAP7…0). In order to access the
correct word in the circular buffer, the PEDIU converts the 7 lsbs of the address into an
8 bits address.
For write operation the conversion is as follows:
bit
DSP
Bit 7
Stream0/1
CB
bit
DSP
Bit 7
Stream0/1
CB
Circular-buffer write/read address in modes 3, 4
In modes 3, 4 the circular buffer is divided into 2 IN blocks and 2 OUT blocks – 64 words
each. This is depicted in Table 2-22 and Figure 2-42.
7
7
1
0
0 = stream 0
1 = stream 1
This field defines if the access is to a block of
IN-stream 0 (DSP-IN0-0, DSP-IN0-1) or of
IN-stream 1 (DSP-IN1-0, DSP-IN1-1).
These should always be ‘0’ during a read operation.
These should contain the prefix of the circular buffer: F0
This is always ‘1’ during a write operation
This field is shifted to bit 6
Current Block (CB) signal negation is inserted as bit 5.
CB is used here because the PEDIU uses CB signal for its own accesses
to the circular buffer. Therefore, in order to access the other blocks during
DSP accesses, CB must be used.For read operation the conversion is as
follows:
This is always ‘0’ during a read operation.
This field is shifted to bit 6.
Current Block (CB) signal negation is inserted as bit 5.
CB is used here because the PEDIU uses CB signal for its own accesses
to the circular buffer. Therefore, in order to access the other blocks during
DSP accesses, CB must be used.
6
stream0/1
6
stream0/1
5
5
CB
CB
4
index(4) index(3) index(2) index(1) index(0)
4
index(4) index(3) index(2) index(1) index(0)
2-112
3
3
Functional Block Description
2
2
1
1
H
.
PEB 20560
0
0
2003-08