1778 - MachXO2: Can I really use the PROGRAMN pin for user i/o without disrupting the ability to program a blank device in-system?

On the MachXO2 device, PROGRAMN is a dual use pin. Our technote TN1204 "MachXO2 Programming and Configuration Usage Guide" describes the behavior of PROGRAMN and other sysCONFIG pins (e.g. INIT, DONE) in detail.

At issue here is that for an erased device PROGRAMN is active by default. There could be conflict if the user circuit has this pin held low during the MachXO2 power-up sequence. Fortunately, the JTAG port will override the PROGRAMN pin in this case.

The user design (bitstream) will load properly. With SDM_PORT=disable PROGRAMN, INIT and DONE are then available for GPIO.

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1778 - MachXO2: Can I really use the PROGRAMN pin for user i/o without disrupting the ability to program a blank device in-system?

1778 - MachXO2: Can I really use the PROGRAMN pin for user i/o without disrupting the ability to program a blank device in-system?

Related Articles

6282 - Diamond: ERROR - par: I/O initial placement is unsuccessful. Check the I/O placement constraints / user preferences (such as pin locking) carefully

6181 - All Nexus / Device Constraint Editor: How can the user set the DONE, INITN, and PROGRAMN pins of Nexus devices as GPIO during user mode?

2002 - ispLEVER: Why does the I/O vector editor in the Device Information window "Expand Option" not generate the I/O vector file (*.iov file) when user clicks “Apply” instead of “Save As"?

7733 - ECP5 / Diamond 3.14: Why does my design get a Map device oversize error related to PLL for LFE5U-12F in with Diamond 3.14, but completes map successfully in earlier releases of Diamond software?

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