KSZ8851SNLI Micrel Inc, KSZ8851SNLI Datasheet - Page 61

• 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

Go-Sleep & Wake-Up Time Register (0xD6 – 0xD7): GSWUTR
This register contains the value which is used to control minimum Go-Sleep time period when the device from normal
power state to low power state or to control minimum Wake-Up time period when the device from low power state to
normal power state in energy detect mode.
August 2009
Micrel, Inc.
Bit
7
6
5-2
1-0
Bit
15-8
Default Value
0
0
0x0
0x0
Default
0x08
R/W
RW
R/W
RW
RW
RO
(W1C)
RW
Description
Bit 8: is corresponding to signal energy detected.
When the bit is set to 1, the PME pin 2 will be asserted when a corresponding wake-on-
LAN event is occurred.
When this bit is set to 0, the PME pin 2 will be not asserted when a corresponding wake-
on-LAN event is occurred.
Auto Wake-Up Enable
This bit is used to enable automatically wake-up from low power state to normal power
state in energy detect mode if carrier (signal energy) is present more than wake-up time in
GSWUTR register. During the normal power state, the device can receive and transmit
packets.
When this bit is set to 1, the auto wake-up is enabled in energy detect mode.
When this bit is set to 0, the auto wake-up is disabled in energy detect mode.
Wake-Up to Normal Operation Mode
This bit is used to control the device wake-up from low power state in energy detect mode
to normal operation mode if signal energy is detected longer than the programmed wake-
up time in GSWUTR register.
When this bit is set to 1, the device will automatically go to the normal operation mode
from energy detect mode.
When this bit is set to 0, the device will not automatically go to the normal mode from
energy detect mode.
This bit is only valid when Auto Wake-Up Enable (bit7) is set to 1.
Wake-Up Event Indication
These four bits are used to indicate the KSZ8851SNL wake-up event status as below:
0000: No wake-up event.
0001: Wake-up from energy event detected. (Bit 2 also set to 1 in ISR register)
0010: Wake-up from link up event detected. (Bit 3 also set to 1 in ISR register)
0100: Wake-up from magic packet event detected.
1000: Wake-up from wakeup frame event detected.
If Wake-on-LAN to PME Output Enable bit[11:8] are set, the KSZ8851SNL also asserts
the PME pin 2. These bits are cleared on power up reset or by write 1. It is not modified
by either hardware or software reset. When these bits are cleared, the KSZ8851SNL de-
asserts the PME pin.
Power Management Mode
These two bits are used to control the KSZ8851SNL power management mode as below:
00: Normal Operation Mode.
01: Energy Detect Mode. (two states in this mode either low power or normal power)
10: Soft Power Down Mode.
11: Power Saving Mode.
In energy detect mode under low power state, it can wake-up to normal operation mode
either from line or host wake-up (host CPU issues any one of registers read or write
access).
In soft power down mode, it can wake-up to normal operation mode only from host wake-
up (host CPU issues any one of registers read or write access).
Description
Wake-up Time
This value is used to control the minimum period that the energy has to be detected
consecutively before the device is waked-up from the low power state. The unit is 16ms
+/-80%, the default wake-up time is 128 ms (16ms x 8). Zero time (0x00) is not allowed
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KSZ8851SNL/SNLI
M9999-083109-2.0