Programming Micron P8P Parallel PCM Flash using Serial Peripheral Interface (SPI) on Medalist i3070 In-Circuit Tester -
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A secondary serial peripheral interface (SPI) has been added on Micron P8P PCM to enable low cost, low pin count on-board programming. This interface gives access to the P8P memory by using only seven signals, instead of a conventional parallel interface that may take 45 signals or more. The seven signals consist of six SPI-only signals plus one signal that is shared with the conventional interface.
When the SPI mode is enabled, all non-SPI P8P output signals are tri-stated, and all non-SPI P8P inputs signals are ignored (made “don’t care”). When the conventional interface is enabled, the SPI-only output is tri-stated, and the SPI-only inputs are ignored (made “don’t care”).