PIC24FJ64GA004 Family Silicon Errata and Data Sheet ... - Microchip

PIC24FJ64GA004 FAMILY51. Module: A/D ConverterOnce the A/D module is enabled(AD1CON1 = 1), it may continue to drawextra current, even if the module is later disabled(AD1CON1 = 0).Work aroundIn addition to disabling the module through theADON bit, set the corresponding PMD bit(ADC1MD, PMD1) to power it downcompletely.Disabling the A/D module through the PMDxregisters also disables the AD1PCFG registers,which in turn, affects the state of any port pinswith analog inputs. Users should consider theeffect on I/O ports and other digital peripheralson those ports when ADC1MD is used for powerconservation.Affected Silicon RevisionsA3/A4B4 B5 B8X X X X52. Module: UART (Transmit Interrupt)When using UTXISEL = 01 (interrupt when the lastcharacter is shifted out of the Transmit Shiftregister) and the final character is being shifted outthrough the Transmit Shift register, the TX interruptmay occur before the final bit is shifted out.Work aroundIf it is critical that the interrupt processing occursonly when all transmit operations are complete,after which the following work around can beimplemented:Hold off the interrupt routine processing by addinga loop at the beginning of the routine that polls theTransmit Shift register empty bit, as shown inExample 2.Affected Silicon RevisionsA3/A4B4 B5 B8X X XEXAMPLE 2:// in UART2 initialization code...U2STAbits.UTXISEL0 = 1;U2STAbits.UTXISEL1 = 0;...DELAYING THE ISR BY POLLING THE TRMT BIT// Set to generate TX interrupt when all// transmit operations are complete.U2TXInterrupt(void){while(U2STAbits.TRMT==0); // wait for the transmit buffer to be empty... // process interruptDS80470G-page 18 2009-2013 Microchip Technology Inc.