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3.2.3.3 Gigabit Ethernet signals
Gigabit Ethernet interface is realised, on Q7-928 module, using a Micrel
through RGMII interface.
Theoretical maximum speed of 1Gbps, however, cannot be reached, due to a known limitation of i.MX6 Gb Ethernet MAC (ENET), which is limited only to
®
470Mbps (also check NXP
Errata ERR004512 for i.MX6 processors).
Here following the signals involved in PCI express management
GBE_MDI0+/GBE_MDI0-: Media Dependent Interface (MDI) I/O differential pair #0
GBE_MDI1+/GBE_MDI1-: Media Dependent Interface (MDI) I/O differential pair #1
GBE_MDI2+/GBE_MDI2-: Media Dependent Interface (MDI) I/O differential pair #2, only used for 1Gbps Ethernet mode (not for 10/100Mbps modes)
GBE_MDI3+/GBE_MDI3-: Media Dependent Interface (MDI) I/O differential pair #3, only used for 1Gbps Ethernet mode (not for 10/100Mbps modes)
GBE_ACT#: Ethernet controller activity indicator. Active Low Output signal, electrical level +3.3V_S
GBE_LINK#: Ethernet controller link indicator, Active Low Output signal. Electrically tied to GBE_ACT# signal.
GBE_LINK100#: Ethernet controller 100Mbps link indicator. Active Low Output signal, electrical level +3.3V_S
GBE_LINK1000#: Ethernet controller 1Gbps link indicator. Active Low Output signal, electrical level +3.3V_S
Please notice that if in the carrier board is needed just a FastEthernet (i.e. 10/100 Mbps) connection, then only MDI0 and MDI1 differential lanes are necessary.
Unused differential pairs and signals can be left unconnected.
3.2.3.4 S-ATA signals
Only one S-ATA interface is available on Q7-928 module. It is managed directly by i.MX6 processor.
Please notice, however, that this SATA interface (which is a SATA II, 3.0 Gbps interface) is available only with i.MX6 Quad and i.MX6 Dual versions, not with i.MX6
Solo or i.MX6 Dual Lite
Here following the signals related to SATA interface:
SATA0_TX+/SATA0_TX-: Serial ATA Channel #0 Transmit differential pair
SATA0_RX+/SATA0_RX-: Serial ATA Channel #0 Receive differential pair
SATA_ACT#: Serial ATA Activity Led. Open collector output at +3.3V_S voltage. It is driven during SATA drive activity.
10nF AC series decoupling capacitors are placed on each line of SATA differential pairs.
Q7-928
Q7-928 User Manual - Rev. First Edition: 1.0 - Last Edition: 3.0 - Author: S.B. - Reviewed by P.Z Copyright © 2016 SECO S.r.l.
®
KSZ9031 Gigabit Ethernet transceiver, which is interfaced to NXP i.MX6 processor
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