Appendix B Physical Characteristics B-13
B.3.5.5 Zone 3 Signal Descriptions
TABLEB-10 provides descriptions of the signals listed in the Zone 3 pin assignment

tables (TABLEB-6 through TABLE B-9).

TABLEB-9 Zone 3 Signal Descriptions
SignalName Description
IPMI_SCL_L IPMI bus clock signal, as definedin AMC.0 specification. RTM shall have a pull-up
resistorfor this signal as indicated in AMC.0 specification.
IPMI_SDA_L IPMI bus data signal, as defined in AMC.0 specification. RTM shall have a pull-up
resistorfor this signal as indicated in AMC.0 specification.
PS0#, PS1# Activelow RTM present signal.PS0# shall be tied to logic GND on the ATCA blade, PS1#
shall be pulled up to 3.3V Management Power on the ATCAblade, PS0# and PS1# shall
be connected throughdiode on RTM,exactly as defined in AMC.0 specification. PS1# is
last mate on Power connector and PS0# is on the opposite end of the set of connectors.
Logic low on PS1# indicates that RTMis presentand fully inserted.
Enable# When low indicates to RTMthat it is fully inserted and that MMC can start execution.
Logic high shall keep MMC in resetstate. This signal shall have a pull-up resistor as
indicated in AMC.0 specification.
Shelf_GND Frame/Chassis Safety Ground.
Logic_GND (Logic0vdc). Logic Ground- Common return for Management Power Payload Power,
referencepotential for single-ended logic signaling, and shielding for differentialpair
signals in the AMC Connector.
12VPP 12V Payload Power,enabled after successful E-keying, following AMC.0 specification.
RTMshall meet requirements posted for payload power in AMC specification.
3.3V_MP 3.3VManagement Power. RTM shall meet requirements posted for management power in
AMC.0 specification.
RTM_RX AMCExtended Options receive differential pair signals. Note that this specification takes
ATCABlade perspective, which means that RX signals are driven by RTM and received
by ATCABlade.
RTM_TX AMC Extended Options transmit differential pair signals. Note that this specification
takes ATCABlade perspective, which means that TX signals are driven by ATCA Blade
and receivedby RTM.
SAS_TX SATA/SAStransmit differential pair signals.
SAS_RX SATA/SASreceive differentialpair signals.
Serial 0 RS-232 Serial Signals, Transmit, Receive, Clear to Send, Request to Send, Data Terminal
Ready,and Data Set Ready.
LAN0 10/100/1000BASE-T signals.
LAN0_CTV 10/100/1000BASE-Ttransformer Center Tap signal, which could be used to terminate
centertap of transformers, if they are placed on RTM. This signal is applicable if Ethernet
PHY is located on ATCAblade, while transformers are located on RTM.