Intel CONTROLLERS 413808 - Manual (Page 743)

Intel ® 413808 and 413812 I/O Controllers in TPER Mode
October 2007 Developer’s Manual
Order Number: 317805-001US 743
PMON Unit—Intel ® 413808 and 413812
16.5 Non-Register-Based Interfaces
This section describes the interfaces to the PMON unit that are not part of the register
scheme already documented.
16.5.1 Events Input Port
Signals representing internal events are sent to the event preconditioning block where
they are conditioned when required. The most common preconditioning is likely to be
clock synchronization. No programmable Boolean operations can be performed on
these events, but appropriate Boolean operations can be performed by the hardware.
Duration type events continually assert their signal high ('1'). The event
pre-conditioning block 'ANDs' the duration type signal with a clock to produce the
correct count.
Any events from different frequency domains must be preconditioned to assure count
accuracy measured. For these clock domain crossing signals, 95% accuracy is sufficient
over a 1 us or larger sampling window. It would be very difficult to assure accuracy of
very small windows (< 1 us) without requiring a great amount of hardware to verify.
16.5.2 Output Signals
There are three potential sources of internal indicators from each counter. Each source
can independently generate an indication. These are:
• a programmable threshold condition was true,
• a command was triggered to begin
• a counter overflow or underflow occurred.
Each of these conditions always sets a corresponding status bit. Indicator enable bits
control which of these indicator sources drive the top level indicator. The indicators are
OR'd together as shown in Figure 118, “Indicator Tree” on page 744 . These internal
signals are further controlled to generate either an Interrupt or an Indicator Output.