Rxnfreebuffer), Section 5.28 – Texas Instruments TMS320C645x DSP User Manual
Page 112
www.ti.com
5.28 Receive Channel 0-7 Free Buffer Count Register (RXnFREEBUFFER)
EMAC Port Registers
The receive channel 0-7 free buffer count register (RXnFREEBUFFER) is shown in
and
described in
Figure 56. Receive Channel n Free Buffer Count Register (RXnFREEBUFFER)
31
16
Reserved
R-0
15
0
RXnFREEBUF
WI-0
tLEGEND: R = Read only; R/W = Read/Write; WI = Write to increment; -n = value after reset
Table 56. Receive Channel n Free Buffer Count Register (RXnFREEBUFFER) Field Descriptions
Bit
Field
Value
Description
31-16
Reserved
0
Reserved
15-0
RXnFREEBUF
Receive free buffer count. These bits contain the count of free buffers available. The
RXFILTERTHRESH value is compared with this field to determine if low priority frames should be
filtered. The RXnFLOWTHRESH value is compared with this field to determine if receive flow
control should be issued against incoming packets (if enabled). This is a write-to-increment field.
This field rolls over to zero on overflow. If hardware flow control or QOS is used, the host must
initialize this field to the number of available buffers (one register per channel). The EMAC
decrements (by the number of buffers in the received frame) the associated channel register for
each received frame. The host must write this field with the number of buffers that have been freed
due to host processing.
Ethernet Media Access Controller (EMAC)/Management Data Input/Output (MDIO)
112
SPRU975B – August 2006