Table of Contents
Advertisement
31
Field
Reset
R/W
15
Field
Reset
R/W
Address
Figure 17-24. Receive Descriptor Ring Start Register (ERDSR)
Bits
31–2
1–0
17.5.4.22 Transmit Buffer Descriptor Ring Start (ETSDR)
The ETSDR is written by the user. It provides a pointer to the start of the circular transmit
buffer descriptor queue in external memory. This pointer must be 32-bit aligned; however,
it is recommended it be made 128-bit aligned (evenly divisible by 16). Bits 1 and 0 should
be written to 0 by the user. Non-zero values in these two bit positions are ignored by the
hardware.
This register is not reset and must be initialized by the user prior to operation.
31
Field
Reset
R/W
15
Field
Reset
R/W
Address
Figure 17-25. Transmit Buffer Descriptor Ring Start Register (ETDSR)
MOTOROLA
R_DES_START
Table 17-33. ERDSR Field Descriptions
Name
R_DES_START Pointer to start of receive buffer descriptor queue.
—
Reserved, should be cleared.
X_DES_START
Chapter 17. Fast Ethernet Controller (FEC)
R_DES_START
Uninitialized
R/W
Uninitialized
R/W
IPSBAR + 0x1180
Descriptions
X_DES_START
Uninitialized
R/W
Uninitialized
R/W
IPSBAR + 0x1184
Programming Model
16
2
1
0
—
16
2
1
0
—
17-43
Advertisement
Table of Contents
