SerDes PHY Register Definitions
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 558
1000XCONTROL3
Register Description:
1000X Control3 Register.
Register Offset:
0x12 at Block 0
Table 136: 1000XCONTROL3
Bits
Name
RW
Description
Default
15
DISABLE_PKT_ALIGNMENT RW
0 = Normal operation.
1 = Disable packet misalignment by carrier extend
and removing preamble.
0
14
RXFIFO_GMII_RST
RW
0 = Normal operation.
1 = Reset receive FIFO and data_out_1000. FIFO
will remain in reset until this bit is cleared with a
software write.
0
13
DISABLE_TX_CRS
RW
0 = Normal operation.
1 = Disable generating crs from transmitting in half-
duplex mode. Only receiving will generate crs.
1
12
INVERT_EXT_PHY_CRS
RW
0 = Use “receive crs from PHY” pin.
1 = Invert “receive crs from PHY” pin
1
11
EXT_PHY_CRS_MODE
RW
0 = Normal operation.
1 = Use external pin for the PHYs “receive only” crs
output. (Useful in SGMII 10/100 half-duplex
applications in order to reduce the collision domain
latency. Requires a PHY, which generates a
“receive only” crs output to a pin.)
1
10
JAM_FALSE_CARRIER_MO
DE
RW
0 = Normal operation.
1 = Change false carriers received into packets with
preamble only. (Not necessary if MAC uses crs to
determine collision)
0
9
BLOCK_TXEN_MODE
RW
0 = Normal operation.
1 = Block txen when necessary to guarantee an ipg
of at least 6.5 bytes in 10/100 mode, 7 bytes in 1000
mode.
0
8
FORCE_TXFIFO_ON
RW
0 = Normal operation.
1 = Force transmit FIFO to free-run in Gigabit mode
(Requires clk_in and pll_clk125 to be frequency
locked.)
0
7
BYPASS_TXFIFO1000
RW
0 = Normal operation.
1 = Bypass transmit FIFO in Gigabit mode. (Useful
for fiber or Gigabit only applications where the MAC
is using the pll_clk125 as the clk_in port. User must
meet timing to the pll_clk125 domain)
0