- at least 6x 16bit timers that can be used for frequency generation (50% duty cycle is sufficient, no pwm)
- 4x ADC
- Internal RC oscillator, at least 16Mhz
- cheap: < $1
- bonus points: programmable logic
What frequency range and granularity do you need ? Is internal or external oscillator needed ?
eg the EFM8LB1 has programmable logic & 72MHz sysclk, so it can produce 16b to up to ~ 1100Hz, and the 6 channel PCA can use HSO mode to SW manage multiple frequencies, up to some SW-overhead limit.
I'd expect something above 100kHz to be possible, via HSO and above 281KHz there is a 8b FreqOut mode, plus the programmable logic can toggle on any timer overflow.