j-flash program slowly

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  • Am I correct to assume you are trying to program the flash of cell phones ?
    If you are, please make sure what you are trying to do is legal.

    On the technical side, things are always similar:

    You should understand the target system:
    Take a look at the schematic and the documentation of your CPU / SOC.
    Make sure the CPU runs at a decent speed (at least a few MHz, not just 32kHz)
    If necessary, enable & select a PLL as clock source.
    Locate RAM (Ideally on-chip RAM, even if it is just a 4KB) in the chip documentation.
    If necessary, use external RAM (usually SDRAM). You may have to setup
    the external bus interface.
    You may also have to setup the external bus interface to program the flash
    since in a lot of cases, it allows per default just reading of flash memory.
    Last but not least, you should make sure the JTAG speed is as
    high as possible (on ARM-S cores with RTCK, Adaptive is usually a good
    choice; if not, 8Mhz or 12MHz is ideal. However, this should be the last step)