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RELEASED
DATA SHEET
PM7366 FREEDM-8
ISSUE 4
PMC-1970930
FRAME ENGINE AND DATA LINK MANAGER
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA,INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
47
Figure 8 – Receive Channel Descriptor Reference Table
RPD Pointer[13:0]
Start RPD Pointer[13:0]
Bytes Available in Buffer[15:0]
Buffer Size[15:0]
DMA Current Address[31:0]
RBC[1:0]
Bit 0
Bit 31
RCC 0
RCC 1
RCC 127
RPD Pointer[13:0]
Start RPD Pointer[13:0]
Bytes Available in Buffer[15:0]
Buffer Size[15:0]
DMA Current Address[31:0]
RPD Pointer[13:0]
Start RPD Pointer[13:0]
Bytes Available in Buffer[15:0]
Buffer Size[15:0]
DMA Current Address[31:0]
RBC[1:0]
RBC[1:0]
V
V
V
Res
Res
Res
Table 10 – Receive Channel Descriptor Reference Table Fields
Field
Description
Bytes Available in
Buffer[15:0]
This field is used to keep track of the number of bytes available in
the current data buffer. The RMAC initialises the Bytes Available in
Buffer to the Receive Buffer Size minus the offset at the head of the
buffer. The field is decremented each time a byte is written into the
buffer.
RBC[1:0]
This field is used to keep track of the number of buffers used when
storing ‘raw’ (i.e. non packet delimited) data. The RMAC initialises
the RBC field to the value of the RAWMAX[1:0] field in the RMAC
Control Register. The field is decremented each time a buffer is
filled with data. If the field reaches zero, the chain of RPDs is
placed on the ready queue and a new chain started.
RPD Pointer[13:0]
This field contains the pointer to the current RPD.
Buffer Size[15:0]
This field contains the size in bytes of the buffer currently being
written to.