I have two identical custom board with LPC4357FET256.
One with 32kHz oscillator crystal connected to chip. And another w/o crystal.
But... On both board ATIMER worked. How it's possible ?
Initialize like this:
LPC_CREG->CREG0 &= ~((1 << 3) | (1 << 2));
LPC_CREG->CREG0 |= (1 << 1) | (1 << 0);
LPC_ATIMER->DOWNCOUNTER = 2048;
LPC_ATIMER->PRESET = 2048;
and put DOWNCOUNTER to LCD:
On both board value changed identical.
UM10503 v2.1 Chapter 36:
"Alarm timer counter register (DOWNCOUNTER, see Table 866), which counts down from a preset value using the
1024 Hz signal derived from the 32 kHz oscillator."
32kHz oscillator crystal NOT present on the second board, but ATIMER is worked...