![](http://datasheet.mmic.net.cn/Micrel-Inc/KSZ8721BI-TR_datasheet_97860/KSZ8721BI-TR_19.png)
March 2006
19
M9999-030106
KS8721B/BT
Micrel, Inc.
Address Name
Description
Mode(Note 1) Default
5.11:10
Pause
5.10 5 .11
RO
0
0 0
No PAUSE
0 1
Asymmetric PAUSE (link partner)
1 0
Symmetric PAUSE
1 1
Symmetric & Asymmetric PAUSE (local device)
5.9
100 BaseT4
1 = T4 capable; 0 = no T4 capability
RO
0
5.8
100BaseTX Full Duplex
1 = TX with full duplex; 0 = no TX full duplex capability
RO
0
5.7
100BaseTX
1 = TX capable; 0 = no TX capability
RO
0
5.6
10BaseT Full Duplex
1 = 10Mbps with full duplex
RO
0
0 = no 10Mbps full duplex capability
5.5
10BaseT
1 = 10Mbps capable; 0 = no 10Mbps capability
RO
0
5.4:0
Selector Field
[00001] = IEEE 802.3
RO
00001
Register 6h - Auto-Negotiation Expansion
6.15:5
Reserved
RO
0
6.4
Parallel Detection Fault
1 = fault detected by parallel detection
RO/LH
0
0 = no fault detected by parallel detection.
6.3
Link Partner Next
1 = link partner has next page capability
RO
0
Page Able
0 = link partner does not have next page capability
6.2
Next Page Able
1 = local device has next page capability
RO
1
0 = local device does not have next page capability
6.1
Page Received
1 = new page received; 0 = new page not yet received
RO/LH
0
6.0
Link Partner
1 = link partner has auto-negotiation capability
RO
0
Auto-Negotiation Able
0 = link partner does not have auto-negotiation capability
Register 7h - Auto-Negotiation Next Page
7.15
Next Page
1 = additional next page(s) will follow; 0 = last page
RW
0
7.14
Reserved
RO
0
7.13
Message Page
1 = message page; 0 = unformatted page
RW
1
7.12
Acknowledge2
1 = will comply with message
RW
0
0 = cannot comply with message
7.11
Toggle
1 = previous value of the transmitted link code word
RO
0
equaled logic One; 0 = logic Zero
7.10:0
Message Field
11-bit wide eld to encode 2048 messages
RW
001
Register 8h - Link Partner Next Page Ability
8.15
Next Page
1 = additional Next Page(s) will follow; 0 = last page
RO
0
8.14
Acknowledge
1 = successful receipt of link word
RO
0
0 = no successful receipt of link word
8.13
Message Page
1 = Message Page; 0 = Unformatted Page
RO
0
8.12
Acknowledge2
1 = able to act on the information
RO
0
0 = not able to act on the information
8.11
Toggle
1 = previous value of transmitted Link Code Word equal
RO
0
to logic zero; 0 = previous value of transmitted Link Code
Word equal to logic one
8.10:0
Message Field
RO
0
Note 1. RW: Read/Write, RO: Read only, SC: Self clear, LH: Latch High, LL: Latch Low. Some of the default values are set by strap-in. See “Srap-
ping Options.”
Address Name
Description
Mode
5.11:10
Pause
5.10 5 .11
RO
0
0 0
0 1
1 0
1 1
5.9
100 BaseT4
1 = T4 capable; 0 = no T4 capability
RO
0
5.8
100BaseTX Full Duplex
1 = TX with full duplex; 0 = no TX full duplex capability
RO
0
5.7
100BaseTX
1 = TX capable; 0 = no TX capability
RO
0
5.6
10BaseT Full Duplex
1 = 10Mbps with full duplex
RO
0
0 = no 10Mbps full duplex capability
5.5
10BaseT
1 = 10Mbps capable; 0 = no 10Mbps capability
RO
0
5.4:0
Selector Field
[00001] = IEEE 802.3
RO
00001
Address Name
Description
Mode
5.11:10
Pause
5.10 5 .11
RO
0
5.9
100 BaseT4
1 = T4 capable; 0 = no T4 capability
RO
0
5.8
100BaseTX Full Duplex
1 = TX with full duplex; 0 = no TX full duplex capability
RO
0
5.7
100BaseTX
1 = TX capable; 0 = no TX capability
RO
0
5.6
10BaseT Full Duplex
1 = 10Mbps with full duplex
RO
0
5.5
10BaseT
1 = 10Mbps capable; 0 = no 10Mbps capability
RO
0
5.4:0
Selector Field
[00001] = IEEE 802.3
RO
00001
Address Name
Description
Mode
5.11:10
Pause
5.10 5 .11
RO
0
0 0
0 1
1 0
1 1
5.9
100 BaseT4
1 = T4 capable; 0 = no T4 capability
RO
0
5.8
100BaseTX Full Duplex
1 = TX with full duplex; 0 = no TX full duplex capability
RO
0
5.7
100BaseTX
1 = TX capable; 0 = no TX capability
RO
0
5.6
10BaseT Full Duplex
1 = 10Mbps with full duplex
RO
0
0 = no 10Mbps full duplex capability
5.5
10BaseT
1 = 10Mbps capable; 0 = no 10Mbps capability
RO
0
5.4:0
Selector Field
[00001] = IEEE 802.3
RO
00001
Default
5.11:10
Pause
5.10 5 .11
RO
0
5.9
100 BaseT4
1 = T4 capable; 0 = no T4 capability
RO
0
5.8
100BaseTX Full Duplex
1 = TX with full duplex; 0 = no TX full duplex capability
RO
0
5.7
100BaseTX
1 = TX capable; 0 = no TX capability
RO
0
5.6
10BaseT Full Duplex
1 = 10Mbps with full duplex
RO
0
5.5
10BaseT
1 = 10Mbps capable; 0 = no 10Mbps capability
RO
0
5.4:0
Selector Field
[00001] = IEEE 802.3
RO
00001
6.15:5
Reserved
RO
0
6.4
Parallel Detection Fault
1 = fault detected by parallel detection
RO/LH
0
0 = no fault detected by parallel detection.
Page Able
0 = link partner does not have next page capability
6.2
Next Page Able
1 = local device has next page capability
RO
1
0 = local device does not have next page capability
6.1
Page Received
1 = new page received; 0 = new page not yet received
RO/LH
0
6.0
Link Partner
1 = link partner has auto-negotiation capability
RO
0
Auto-Negotiation Able
0 = link partner does not have auto-negotiation capability
6.15:5
Reserved
RO
0
6.4
Parallel Detection Fault
1 = fault detected by parallel detection
RO/LH
0
1 = link partner has next page capability
RO
0
6.2
Next Page Able
1 = local device has next page capability
RO
1
6.1
Page Received
1 = new page received; 0 = new page not yet received
RO/LH
0
6.0
Link Partner
1 = link partner has auto-negotiation capability
RO
0
6.15:5
Reserved
RO
0
6.4
Parallel Detection Fault
1 = fault detected by parallel detection
RO/LH
0
0 = no fault detected by parallel detection.
1 = link partner has next page capability
RO
0
Page Able
0 = link partner does not have next page capability
6.2
Next Page Able
1 = local device has next page capability
RO
1
0 = local device does not have next page capability
6.1
Page Received
1 = new page received; 0 = new page not yet received
RO/LH
0
6.0
Link Partner
1 = link partner has auto-negotiation capability
RO
0
Auto-Negotiation Able
0 = link partner does not have auto-negotiation capability
6.15:5
Reserved
RO
0
6.4
Parallel Detection Fault
1 = fault detected by parallel detection
RO/LH
0
1 = link partner has next page capability
RO
0
6.2
Next Page Able
1 = local device has next page capability
RO
1
6.1
Page Received
1 = new page received; 0 = new page not yet received
RO/LH
0
6.0
Link Partner
1 = link partner has auto-negotiation capability
RO
0
7.15
Next Page
1 = additional next page(s) will follow; 0 = last page
RW
0
7.14
Reserved
RO
0
7.13
Message Page
1 = message page; 0 = unformatted page
RW
1
7.12
Acknowledge2
1 = will comply with message
RW
0
0 = cannot comply with message
7.11
Toggle
1 = previous value of the transmitted link code word
RO
0
equaled logic One; 0 = logic Zero
7.10:0
Message Field
11-bit wide eld to encode 2048 messages
RW
001
7.15
Next Page
1 = additional next page(s) will follow; 0 = last page
RW
0
7.14
Reserved
RO
0
7.13
Message Page
1 = message page; 0 = unformatted page
RW
1
7.12
Acknowledge2
1 = will comply with message
RW
0
7.11
Toggle
1 = previous value of the transmitted link code word
RO
0
7.10:0
Message Field
11-bit wide eld to encode 2048 messages
RW
001
7.15
Next Page
1 = additional next page(s) will follow; 0 = last page
RW
0
7.14
Reserved
RO
0
7.13
Message Page
1 = message page; 0 = unformatted page
RW
1
7.12
Acknowledge2
1 = will comply with message
RW
0
0 = cannot comply with message
7.11
Toggle
1 = previous value of the transmitted link code word
RO
0
equaled logic One; 0 = logic Zero
7.10:0
Message Field
11-bit wide eld to encode 2048 messages
RW
001
7.15
Next Page
1 = additional next page(s) will follow; 0 = last page
RW
0
7.14
Reserved
RO
0
7.13
Message Page
1 = message page; 0 = unformatted page
RW
1
7.12
Acknowledge2
1 = will comply with message
RW
0
7.11
Toggle
1 = previous value of the transmitted link code word
RO
0
7.10:0
Message Field
11-bit wide eld to encode 2048 messages
RW
001
5.11:10
Pause
5.10 5 .11
RO
0
0 0
0 1
1 0
1 1
5.8
100BaseTX Full Duplex
1 = TX with full duplex; 0 = no TX full duplex capability
RO
0
5.7
100BaseTX
1 = TX capable; 0 = no TX capability
RO
0
5.6
10BaseT Full Duplex
1 = 10Mbps with full duplex
RO
0
0 = no 10Mbps full duplex capability
5.5
10BaseT
1 = 10Mbps capable; 0 = no 10Mbps capability
RO
0
5.4:0
Selector Field
[00001] = IEEE 802.3
RO
00001
6.15:5
Reserved
RO
0
6.4
Parallel Detection Fault
1 = fault detected by parallel detection
RO/LH
0
0 = no fault detected by parallel detection.
6.3
Page Able
0 = link partner does not have next page capability
6.2
Next Page Able
1 = local device has next page capability
RO
1
0 = local device does not have next page capability
6.1
Page Received
1 = new page received; 0 = new page not yet received
RO/LH
0
6.0
Link Partner
1 = link partner has auto-negotiation capability
RO
0
Auto-Negotiation Able
0 = link partner does not have auto-negotiation capability
7.15
Next Page
1 = additional next page(s) will follow; 0 = last page
RW
0
7.14
Reserved
RO
0
7.13
Message Page
1 = message page; 0 = unformatted page
RW
1
7.12
Acknowledge2
1 = will comply with message
RW
0
0 = cannot comply with message
7.11
Toggle
1 = previous value of the transmitted link code word
RO
0
equaled logic One; 0 = logic Zero
7.10:0
Message Field
11-bit wide eld to encode 2048 messages
RW
001
Register 8h - Link Partner Next Page Ability
8.15
Next Page
1 = additional Next Page(s) will follow; 0 = last page
RO
0
8.14
Acknowledge
1 = successful receipt of link word
RO
0
0 = no successful receipt of link word
8.13
Message Page
1 = Message Page; 0 = Unformatted Page
RO
0
8.12
Acknowledge2
1 = able to act on the information
RO
0
0 = not able to act on the information
8.11
Toggle
1 = previous value of transmitted Link Code Word equal
RO
0
to logic zero; 0 = previous value of transmitted Link Code
Word equal to logic one
8.10:0
Message Field
RO
0
8.15
Next Page
1 = additional Next Page(s) will follow; 0 = last page
RO
0
8.14
Acknowledge
1 = successful receipt of link word
RO
0
0 = no successful receipt of link word
8.13
Message Page
1 = Message Page; 0 = Unformatted Page
RO
0
8.12
Acknowledge2
1 = able to act on the information
RO
0
0 = not able to act on the information
8.11
Toggle
1 = previous value of transmitted Link Code Word equal
RO
0
to logic zero; 0 = previous value of transmitted Link Code
Word equal to logic one
8.10:0
Message Field
RO
0
8.15
Next Page
1 = additional Next Page(s) will follow; 0 = last page
RO
0
8.14
Acknowledge
1 = successful receipt of link word
RO
0
8.13
Message Page
1 = Message Page; 0 = Unformatted Page
RO
0
8.12
Acknowledge2
1 = able to act on the information
RO
0
8.11
Toggle
1 = previous value of transmitted Link Code Word equal
RO
0
8.10:0
Message Field
RO
0
8.15
Next Page
1 = additional Next Page(s) will follow; 0 = last page
RO
0
8.14
Acknowledge
1 = successful receipt of link word
RO
0
0 = no successful receipt of link word
8.13
Message Page
1 = Message Page; 0 = Unformatted Page
RO
0
8.12
Acknowledge2
1 = able to act on the information
RO
0
0 = not able to act on the information
8.11
Toggle
1 = previous value of transmitted Link Code Word equal
RO
0
to logic zero; 0 = previous value of transmitted Link Code
Word equal to logic one
8.10:0
Message Field
RO
0
8.15
Next Page
1 = additional Next Page(s) will follow; 0 = last page
RO
0
8.14
Acknowledge
1 = successful receipt of link word
RO
0
8.13
Message Page
1 = Message Page; 0 = Unformatted Page
RO
0
8.12
Acknowledge2
1 = able to act on the information
RO
0
8.11
Toggle
1 = previous value of transmitted Link Code Word equal
RO
0
8.10:0
Message Field
RO
0