peb20560 Infineon Technologies Corporation, peb20560 Datasheet - Page 143

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

2.8.2.2
The USR is the status register of the PEDIU. Its content may be used by the programmer
to find out the status of the PEDIU. This register has only one bit − the most significant
bit: CB.
DSP reads USR from the address 0xC101. The 15 lsbs will be read as ‘0’.
bit
USR
It is not possible to write to USR.
After reset the USR register is “0000
CB
CB is inverted at the start of every new frame, immediately after rising edge sampling of
FSC by the PEDIU. After reset or when the PEDIU is in idle mode (UCR:ACTIVEP = 0),
CB is updated to ‘0’. In the first frame after PEDIUs activation (set UCR:ACTIVEP to ‘1’),
CB will be ‘1’.
Figure 2-43 describes the function of CB when PEDIU work mode is 0, 1 or 2 and
Figure 2-44 describes the function of CB when PEDIU work mode is 3 or 4.
Semiconductor Group
Current Block
The CB bit indicates the state of the circular buffer during the current frame. CB
indicates the blocks of the circular buffer the accessed by the PEDIU in this frame
and those that should be accessed by the DSP. The exact meaning of CB
depends on the work mode of the PEDIU, as this mode defines the circular buffer
structure, as can be seen in Table 2-22.
CB = ‘0’: When PEDIU mode is 0, 1 or 2:
CB = ‘1’: When PEDIU mode is 0, 1 or 2:
15
CB
PEDIU Status Register (USR)
0
During the current frame the PEDIU reads from circular buffer blocks
DSP-OUT0 - 0 and DSP-OUT1 - 0 and writes into DSP-in0 - 0 and
DSP-in1 - 0. When PEDIU mode is 3 or 4:
During the current frame the PEDIU reads from circular buffer blocks
DSP-OUT0 - 0 and writes into DSP-in0 - 0. For more details see
Table 2-22, which explains the circular buffer block.
During the current frame the PEDIU reads from circular buffer blocks
DSP-OUT0 - 1 and DSP-OUT1 - 1 and writes into DSP-in0 - 1 and
DSP-in1 - 1. When PEDIU mode is 3 or 4:
During the current frame the PEDIU reads from circular buffer blocks
DSP-OUT0 - 1 and writes into DSP-in0 - 1. For more details see
Table 2-22, which explains the circular buffer block structure in each
mode.
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0
0
0
H
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2-97
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Functional Block Description
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PEB 20560
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2003-08
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