KSZ8851SNLI Micrel Inc, KSZ8851SNLI Datasheet - Page 41

• Manufacturer Part Number: KSZ8851SNLI
• Manufacturer: Micrel Inc

Specifications of KSZ8851SNLI

• Operating Supply Voltage (typ): 3.3V
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 32
• Lead Free Status / RoHS Status: Supplier Unconfirmed

MARH[15:0] = 0x0123
Host MAC Address Register Low (0x10 – 0x11): MARL
The following table shows the register bit fields for Low word of Host MAC address.
Host MAC Address Register Middle (0x12 – 0x13): MARM
The following table shows the register bit fields for middle word of Host MAC address.
Host MAC Address Register High (0x14 – 0x15): MARH
The following table shows the register bit fields for high word of Host MAC address.
0x16 – 0x1F: Reserved
On-Chip Bus Control Register (0x20 – 0x21): OBCR
This register controls the on-chip bus clock speed for the KSZ8851SNL. The default of the on-chip bus clock speed is 125
MHz. When the external host CPU is running at a higher clock rate, the on-chip bus should be adjusted for the best
performance.
August 2009
Micrel, Inc.
Bit
15-0
Bit
15-0
Bit
15-0
Bit
15-7
6
5-3
2
1-0
-
-
-
-
0
0
Default Value
Default Value
Default Value
Default Value
0x0
0x0
R/W
RW
R/W
RW
R/W
RW
R/W
RO
RW
RO
RW
RW
Description
MARL MAC Address Low
The least significant word of the MAC address.
Description
MARM MAC Address Middle
The middle word of the MAC address.
Description
MARH MAC Address High
The Most significant word of the MAC address.
Description
Reserved
Output Pin Drive Strength
Bi-directional or output pad drive strength selection.
0: 8 mA
1: 16 mA
Reserved
On-Chip Bus Clock Selection
0: 125 MHz (default setting is divided by 1, Bit[1:0]=00)
1: NA (reserved)
On-Chip Bus Clock Divider Selection
00: Divided by 1.
01: Divided by 2.
10: Divided by 3.
11: NA (reserved).
For example to contol the bus clock speed as below:
If Bit 2 = 0 and this value is set 00 to select 125 MHz.
If Bit 2 = 0 and this value is set 01 to select 62.5 MHz.
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KSZ8851SNL/SNLI
M9999-083109-2.0