Functions
MONITOR_FALLING_EDGES
EDGE DETECTION API

The MONITOR_FALLING_EDGES procedure requests a strobe a strobe signal (logic '1' value for one clock cycle) to be sent from the framework to the application module when a falling edge is detected signal on a signal of interest. The strobe signal occurs 1 clock cycle after the sampled high to low transition of the input signal.

However, in many use cases, the strobe signal need not be read by the application module. Instead, if the caller specifies a transition_state other than -1 (no_trans), then the framework will schedule a state machine transition to the specified state on the same clock cycle that the strobe is asserted.

There can be multiple falling edge detectors on the same resource domain, thus each individual falling edge detector is identified by a edge_index.

Usage Examples

Todo:
Add Example Usage

Example API Call(s):

MONITOR_FALLING_EDGES(0, input_sig, st_start, next_state_rec, state_reg_rec );

Call Data [ 5 parameters (5 mandatory) ]

Parameters
[in]edge_index[1] index of the array FALLING_EDGE vector that is returned by the framework
[in]input_signal[2] signal to be monitored for a low to high transition
[in]transition_state[3] integer state to transition to after a falling edge detection of input_signal
[out]next_state_rec[4]
[in]state_reg_rec[5]

Return Data

Parameters
[in]state_reg_rec(M).falling_edge(N)[1] [std_logic] value returned from framework

Command Reference

Voice and Hotkey Commands:

See also
Monitor Falling Edges Commands

Command Parameter Mapping

Parameters
[in]edge_index[1] "index <integer>"
[in]input_signal[2] "data <std_logic>"
[in]transition_state[3] "go to [state] (<state>|<integer>)"
[out]next_state_rec[4]
[in]state_reg_rec[5]

Command Return Data

Parameters
[in]state_reg_rec(M).falling_edge(N)[1] [std_logic] "falling edge <integer>"

Voice/HotKey Command Sequence

MONITOR_FALLING_EDGES( 0, input_signal(1), st_start, next_state_rec, state_reg_rec );

Voice Command HotKey Sequence
"monitor falling edge zero" mf0
"data input signal one" data input_signal(1)
"goto state start" goto st_start

Notes and Warnings

Note
  1. The caller is responsible for indexing falling_edge(N) when the call is made when reading strobes.
  2. When indexing state_reg_rec(M).falling_edge(N), 'M' represents the resource index and 'N' represents the edge_index
  3. A rising_edge detection circuit is utilized when the CONFIGURE_COUNTER call specifies an enable parameter with a boolean expression
See also
MONITOR_RISING_EDGES

Procedures

  MONITOR_FALLING_EDGES(
edge_index: natural
input_signal: std_logic
transition_state: STATE_INTEGER
signal next_state_rec: out NSR
state_reg_rec: in SRR
)
  MONITOR_FALLING_EDGES(
edge_index: natural
input_signal: std_logic
transition_state: STATE_INTEGER
signal next_state_rec: out NSR_ARRAY
state_reg_rec: in SRR_ARRAY
)
 overloaded for array interface