nRF51822 SPI frequency fine tune

[Frank Zhao]

the nRF51822 reference manual says the bit rates for SPI are

K125 0x02000000 125 kbps K250 0x04000000 250 kbps K500 0x08000000 500 kbps M1 0x10000000 1 Mbps M2 0x20000000 2 Mbps M4 0x40000000 4 Mbps M8 0x80000000 8 Mbps

Is it possible to slightly fine tune the bit rate by ORing these masks? I am using SPI to generate a timing strict waveform, not for actual communication.

[Hung Bui]

The FREQUENCY register actually is a single byte register, the options are fixed and you can't tweak it to get different bit rates.

[Frank Zhao]

even a timer is too slow, I can't write to the compare register fast enough, even with assembly