
Micrel, Inc.
KSZ8842-PMQL/PMBL
October 2007
82
M9999-100207-1.5
Port 1 Control Register 4 (Offset 0x0512): P1CR4
This register contains the global per port control for the switch port 1 function.
Bit
Default
R/W
Description
Is the same as:
15
0
RW
LED off
1 = Turn off all port 1’s LEDs (LED1_3, LED1_2,
LED1_1, LED1_0). These pin/balls will be driven
high if this bit is set to one.
0 = normal operation
P1MBCR, bit 0
14
0
RW
Txids
1 = disable port’s transmitter
0 = normal operation
P1MBCR, bit 1
13
0
RW
Restart AN
1 = restart auto-negotiation
0 = normal operation
P1MBCR, bit 9
12
0
RW
Disable Far end fault
1 = disable far end fault detection & pattern
transmission.
0 = enable far end fault detection & pattern
transmission.
P1MBCR, bit 2
11
0
RW
Power down
1 = power down
0 = normal operation
P1MBCR, bit 11
10
0
RW
Disable auto MDI/MDIX
1 = disable auto MDI/MDIX function
0 = enable auto MDI/MDIX function
P1MBCR, bit 3
9
0
RW
Force MDIX
1 = If auto MDI/MDIX is disabled, force PHY into
MDIX mode
0 = Do not force PHY into MDIX mode
P1MBCR, bit 4
8
0
Loop back
1 = perform loop back, as indicated:
Start: RXP2/RXM2 (port 2)
Loop back: PMD/PMA of port 1’s PHY
End: TXP2/TXM2 (port 2)
0 = normal operation
P1MBCR, bit 14
7
1
RW
Auto Negotiation Enable
0 = disable auto negotiation, speed and duplex are
decided by bit 6 and 5 of the same register.
1 = auto negotiation is ON
P1MBCR, bit 12
6
0
RW
Force Speed
1 = force 100Base-T if AN is disabled (bit 7)
0 = force 10Base-T if AN is disabled (bit 7)
P1MBCR, bit 13
5
0
RW
Force duplex
1 = force full duplex if (1) AN is disabled or (2) AN is
enabled but failed.
0 = force half duplex if (1) AN is disabled or (2) AN
is enabled but failed.
P1MBCR, bit 9