LCMXO2280C-M-EVN Lattice, LCMXO2280C-M-EVN Datasheet - Page 11

• Manufacturer Part Number: LCMXO2280C-M-EVN
• Description: Microcontroller Modules & Accessories MachXO Mini Dev Kit
• Manufacturer: Lattice
• Series: MachXOr
• Type: PLDr

Specifications of LCMXO2280C-M-EVN

• Silicon Manufacturer: Lattice
• Silicon Core Number: LCMXO2280C-4TN144C
• Silicon Family Name: MachXO
• Rohs Compliant: Yes
• Contents: Board, Cables, Documentation
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: LCMXO2280C-3FTN256C

Lattice Semiconductor
MachXO Sleep Mode Demo
The MachXO sleep mode demo illustrates one possible implementation for power savings. Using this method, the
MachXO device provides supervisory logic to control its own SLEEPN pin. Periodically, the device becomes active
to monitor a trigger event. If the event is not present, it deactivates to save power.
When the SLEEPN pin is asserted (low), the following occur:
• The device powers down internally, dropping power consumption to less than 100µA
• All I/Os are tristated
When the SLEEPN pin is de-asserted (high), power is restored and the MachXO is reconfigured and ready to oper-
ate in 1ms or less. Due to the dramatic reduction in power consumption and the fast “instant-on” capability, a
scheme can be implemented with a few simple, inexpensive external components deactivate the device and reacti-
vate with a duty cycle ratio that saves substantial power.
Figure 3. Sleep Circuit (Abbreviated)
When I/O pin 89 goes low, C60 discharges. PNP transistor Q5 then conducts, discharging C59. Provided SW1D is
closed, this value is forced onto the SLEEPN pin of the MachXO device, putting it into low power sleep mode.
Once in sleep mode, all I/O pins are tristated, allowing C60 to slowly charge. This then turns off Q5 and allows C59
to charge. Once the amount of charge is sufficient to place a logic high level on SLEEPN, the device returns to nor-
mal operating mode.
The MachXO begins operating, as defined by its programmed function. In this demonstration, I/O pin 89 is driven
high initially to allow the device an opportunity to remain active long enough to check whether switch S1 is pressed.
If S1 is not pressed, I/O pin 89 is driven low and the cycle repeats.
If S1 is pressed at that moment, the device remains operational for the entire cycle of an internal counter (~3 sec)
and the LEDs are illuminated during this time. S1 is then checked after each subsequent cycle.
To exit sleep mode or to reprogram the device, open switch SW1D (SW1-4).
Download and Program the MachXO Sleep Mode Demo Design
To download the MachXO Sleep Mode Demo source files and reprogram the Mini board:
1. See the Download Demo Designs and Programming Demo Designs with ispVM sections of this document.
2. Use .\Demo_MachXO_Mini_Sleep\project\mini_auto_sleep.jed to restore the MachXO Sleep Mode demo
design.
S1
R56
10K
I/O (14)
MachXO
SLEEPN (70)
I/O (89)
11
0.33uF
C60
R20
10K
R59
10K
MachXO Mini Development Kit
SW1D
Q5
33uF
C59
User’s Guide