Can be found here.
The ARM peripheral bus
Timer0 free running micro-second
counter (TIMER command)
Timer1 used on ARMweb or with ON TIMER
Timer1 setup as 1msec timer, may be reprogrammed
Timer1 , Timer2 and Timer3 used for HWPWM on ARMmite or ARMexpress LITE
Uart0 UART for debug/download
Uart1-3 Not Used unless requested by user with BAUD(1) .. BAUD(3)
PWM used when HWPWM is engaged on PROplus, SuperPRO
I2C Not Used
RTC used for time-keeping
Interrupt use -- 21xx
FIQ not used
ISR2 PWM -- only used by ARMweb
ISR3 UART1 if RXD1, TXD1 used
ISR4 EINT0 if ON EINT0 used
ISR5 EINT1 if ON EINT1 used
ISR6 EINT2 if ON EINT2 used
ISR7 TIMER1 if ON TIMER used
ARMweb has EINT0 connected to ENC28J60,
but it is not used and available to the user.
ARMweb firmware also uses EINT2 for remote debugging.
Interrupt use -- 175x
If a function is not included in the BASIC code the interrupt is available, for instance RXD(1) uses the UART1 interrupt.
Except for the ARMweb, the only background tasks are interrupt handlers for UART0 and UART1. UART1 is not active until the BAUD(1) is assigned.