PM7384 FREEDM-84P672
DATA SHEET
PMC-1990445
ISSUE 5
FRAME ENGINE AND DATA LINK MANAGER 84P672
Transmit Descriptor Table can contain a maximum of 32768 TDs. The base of
the Transmit Descriptor Table is user programmable using the TMAC Tx
Descriptor Table Base register. Thus, as shown below, each TD can be located
using a Transmit Descriptor Reference (TDR) combined with the TMAC Tx
Descriptor Table Base register.
Figure 11 – Transmit Descriptor Table
TDTB[31:4] = Tx Descriptor Table Base register
TDR[14:0] = Transmit Descriptor Reference
TD_ADDR[31:0] = Transmit Descriptor Address
Bit 31
Bit 0
0000
TDTB[31:4]
+
0000
TDR[14:0]
=
TD_ADDR[31:0]
Bit 31
Bit 0
TDTB
Dword 0
Dword 1
Dword 2
Dword 3
Dword 0
TD1
TD2
TD_ADDR
Dword 3
Dword 0
Dword 3
TD 32768
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
64
PMC [ PMC-SIERRA, INC ]
