1323 - Is PROGRAMN pin independent of JTAG programming operations?
The PROGRAMN pin does not affect the JTAG state machine or boundary scan cells. However, the PROGRAMN pin does clear the SRAM configuration memory of the device.
Because of this, a logic low signal on PROGRAMN pin at any time during JTAG configuration process may result in a failure due to the SRAM cells being cleared independent of the configuration process. Therefore it is important that the PROGRAMN pin is held at logic high during the configuration process.
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1263 - Can the PROGRAMN pin be held low for a period of time during power-up to prevent the FPGA from configuring?
Yes, PROGRAMN pin can be used to hold FPGA from configuring. The are cases where user is using SPI programming mode and would like to control the exact time to begin configuration with PROGRAMN pin. Lattice FPGA enter configuration mode when one of ...
1681 - MachXO2: What happens if the PROGRAMN pin is toggled before device configuration is completed when in SPI configuration mode?
The PROGRAMN pin is used by the MachXO2 configuration logic to initiate programming of the device. Generally this pin is held inactive high during configuration. In the MachXO2, SPI configuration will restart when PROGRAMN is toggled during ...
2115 - MachXO2/XO3: While programming the Lattice MachXO2 device using JTAG pins, is it recommended to provide connections to the DONE, INITN, and PROGRAMN pins of the device, or are TCK, TMS, TDI, and TDO sufficient?
In Lattice MachXO2/XO3 devices, JTAG ports can access both Flash and SRAM Memory. Therefore, it is not necessary to use INIT, DONE and PROGRAMN pins. TCK, TMS, TDI and TDO pins are sufficient to program and configure the device. For more details, ...
6179 - How do user program Lattice FPGA after programming a bitstream to the SPI Flash with JTAG_PORT and MASTER_SPI_PORT set to DISABLED?
Description: When JTAG_PORT and MASTER_SPI_PORT is set to DISABLED, user can no longer access the configuration logic through JTAG and MSPI Port. Thus, user can't perform programming with the interface. Solution: To workaround on this, user can ...
2990 - MachXO2: If MachXO2 is in the Feature Row Hardware Default Mode state (erased state) and PROGRAMN is held LOW, then would the device block the JTAG port from accessing the internal flash, or block the access to other devices in the JTAG chain?
Definition: No, the device will not block the JTAG from either accessing the internal Flash or accessing the other devices in the JTAG chain. The PROGRAMN pin is transition sensitive, and not level sensitive.