
E T H E R N E T C O M M U N I C A T I O N M O D U L E
RX Free Buffer register
326
Hardware Reference NS9215
Register
Register bit
assignment
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R X F r e e B u f f e r r e g i s t e r
Address: A060 0A3C
So the
RX_RD
logic knows when the software is freeing a buffer for reuse, the
software writes to the RXFREE register each time it frees a buffer in one of the
pools. RXFREE has an individual bit for each pool; this bit is set to 1 when the
register is written. Reads to RXFREE always return all 0s.
Register
Register bit
assignment
Reserved
TXOFF
13
12
11
10
9
8
7
6
5
4
3
2
1
0
15
14
31
29
28
27
26
25
24
23
22
21
20
19
18
17
16
30
Reserved
Bits
Access
Mnemonic
Reset
Description
D31:10
N/A
Reserved
N/A
N/A
D09:00
R
TXOFF
0x000
Contains a 10-bit byte offset from the start of the transmit
ring in the TX buffer descriptor RAM. The offset is
updated at the end of the TX packet, and will have the
offset to the next buffer descriptor that will be used.
TXOFF can be used to determine from where the
TX_WR
logic will grab the next packet.
Reserved
RX
FREED
RX
FREEA
13
12
11
10
9
8
7
6
5
4
3
2
1
0
15
14
31
29
28
27
26
25
24
23
22
21
20
19
18
17
16
30
Reserved
RX
FREEC
RX
FREEB
Bits
Access
Mnemonic
Reset
Description
D31:04
N/A
Reserved
N/A
N/A
D03
W
RXFREED
0
Pool D free bit
D02
W
RXFREEC
0
Pool C free bit
Summary of Contents for NS9215
Page 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Page 3: ......
Page 4: ......
Page 26: ...26 Hardware Reference NS9215...
Page 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Page 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Page 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Page 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Page 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Page 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Page 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Page 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Page 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Page 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...