JTAG devices requiring external feedback resistor for XTAL
08/232/2015 | 06:50 PM
Do the JTAG devices in the C8051F12x, C8051F04x, or C8051F02x family require a 10 MOhm external feedback resistor for their external crystal oscillator circuits? The datasheets for these devices list a circuit with both the resistor included and excluded.
These devices have an internal 10 MOhm feedback resistor and thus do not require an external one. On later devices (C8051F3xx and later), this external resistor is required.