122 PPC11A 6U VME Single Board Computer
Publication No. PPC11A-HRM/1
6.2.4 PMC Signal Descriptions
Table 6-11 PMC Signal Descriptions
Signal
Description
ACK64~
Acknowledge 64 Bit. Driven low by PCI agent in response to REQ64
AD[63:00]
Address/Data bits. Multiplexed address and data bus
BUSMODE[2:4]
Bus mode. Driven by the host to indicate the bus mode. On the PPC11A this is always PCI. BUSMODE2 is pulled-up.
BUSMODE3 and BUSMODE4 are pulled down to GND
BUSMODE1
Bus Mode 1. Driven low by a PMC if it supports the current bus mode. Used to detect the presence of a PMC on the site
CBE[7:0]~
Command/Byte Enables. During the address phase, these signals specify the type of cycle to carry out on the PCI bus.
During the data phase the signals are byte enables that specify the active bytes on the bus
CLK
Clock. All PCI bus signals except RST~ are synchronous to this clock
DEVSEL~
Device Select. Driven low by a PCI agent to signal that it has decoded its address as the target of the current access
EREADY
The PMC uses this signal to indicate when it is ready to be enumerated by the PCI software.
Reflected in the appropriate XMC/PMC Site Status Register (offset
FRAME~
FRAME. Driven low by the current master to signal the start and duration of an access
GND
Signal Ground
GNT_A/B~
Grant. Driven low by the arbiter to grant PCI bus ownership to a PCI agent
IDSELA/B
Initialization Device Select. Device chip select during configuration cycles
INT[A:D]~
Interrupt lines. Level-sensitive, active-low interrupt requests (rotated between PMC sites)
IRDY~
Initiator Ready. Driven low by the initiator to signal its ability to complete the current data phase
LOCK~
LOCK. Driven low to indicate an atomic operation that may require multiple transactions to complete
M66EN
Used to determine whether a PMC is 66 MHz PCI capable
MONARCH~
Monarch mode is not supported on the PPC11A. This signal is pulled high
N/C
No connection
N12V_AUX
-12 V auxiliary supply pins
P12V_AUX
+12 V auxiliary supply pins
P3V3
+3.3 V supply pins
P5V
+5 V supply pins
PAR
Parity. Parity protection bit for AD31 to AD0 and BE3 to BE0
PAR64
Parity. Parity protection bit for AD63 to AD32
PCI_RSVD
Position reserved by PCI specification
PERR~
Parity Error. Driven low by a PCI agent to signal a parity error
PMC_RSVD
Position reserved by PMC specification
REQ_A/B~
Request. Driven low by a PCI agent to request ownership of the PCI bus
REQ64~
Request 64 Bit. Driven low by PCI master to request 64-bit transfer
RESET
Reset to the PMC. Driven low to reset the PCI bus
RESET_OUT~
Reset output. This signal can be driven by a Monarch PMC to reset the PPC11A
SERR~
System Error. Driven low by a PCI agent to signal a system error
STOP~
STOP. Driven low by a PCI target to signal a disconnect or target-abort
TCK
Test Clock. Clock for the PMC JTAG
TDI
Test Data In. Input data for PMC JTAG chain
Continued overleaf