Data Sheet

Ethernet Controller I210 — Programming Interface
384
The bit mappings are listed in Table 8-8 for clarity.
Note: If software uses the EE_RST function and desires to retain current configuration information,
the contents of the control registers should be read and stored by software. Control register
values are changed by a read of the Flash, which occurs after asserting the EE_RST bit.
Note: The Flash reset function can read configuration information out of the Flash, which affects the
configuration of PCIe space BAR settings. The changes to the BARs are not visible unless the
system reboots and the BIOS is allowed to re-map them.
The SPD_BYPS bit performs a similar function to the CTRL.FRCSPD bit in that the I210’s
speed settings are determined by the value software writes to the CRTL.SPEED bits. However,
with the SPD_BYPS bit asserted, the settings in CTRL.SPEED take effect immediately rather
than waiting until after the I210’s clock switching circuitry performs the change.
8.2.4 Media Dependent Interface (MDI) Control Register - MDIC
(0x0020; R/W)
Software uses this register to read or write MDI registers in the internal PHY or an external SGMII PHY.
Table 8-8. Mappings for SDI Pins Used as GPI
SDP Pin Used as GPI CTRL_EXT Field Settings
Resulting ICR Bit
(GPI)
Direction Enable as GPI Interrupt
3 SDP3_IODIR SDP3_GPIEN 14
2 SDP2_IODIR SDP2_GPIEN 13
1 SDP1_IODIR SDP1_GPIEN 12
0 SDP0_IODIR SDP0_GPIEN 11
Field Bit(s) Initial Value Description
DATA 15:0 X
Data
In a Write command, software places the data bits and the MAC shifts them
out to the PHY. In a Read command, the MAC reads these bits serially from
the PHY and software can read them from this location.
REGADD 20:16 0x0 PHY Register Address: Reg. 0, 1, 2,...31
Reserved 25:21 0x0
Reserved.
Write 0b, ignore on read.
OP 27:26 0x0
Opcode
01b = MDI write.
10b = MDI read.
All other values are reserved.
R (RWM) 28 1b
Ready Bit
Set to 1b by the I210 at the end of the MDI transaction (for example,
indication of a read or write completion). It should be reset to 0b by
software at the same time the command is written.