Texas Instruments TMS320DM643X DMP Receive Channel 0-7 Free Buffer Count Register RXnFREEBUFFER

Models: TMS320DM643X DMP

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Ethernet Media Access Controller (EMAC) Registers

5.27 Receive Channel 0-7 Free Buffer Count Register (RXnFREEBUFFER)

 

The receive channel 0-7 free buffer count register (RXnFREEBUFFER) is shown in Figure 53 and

 

described in Table 52.

 

Figure 53. Receive Channel n Free Buffer Count Register (RXnFREEBUFFER)

31

16

 

Reserved

 

R-0

15

0

 

RXnFREEBUF

WI-0

LEGEND: R = Read only; WI = Write to increment; -n= value after reset

Table 52. Receive Channel n Free Buffer Count Register (RXnFREEBUFFER) Field Descriptions

Bit

Field

Value

Description

31-16

Reserved

0

Reserved

15-0

RXnFREEBUF

0-FFh

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 0 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 the associated channel register for each received frame by the number of buffers in the received frame. The host must write this field with the number of buffers that have been freed due to host processing.

SPRU941A –April 2007Ethernet Media Access Controller (EMAC)/ 93

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Texas Instruments TMS320DM643X DMP manual Receive Channel 0-7 Free Buffer Count Register RXnFREEBUFFER