TRM: Information about Peripherals, peripheral implementtaiton, register sets, register config, clocks
Datasheet: Information about Pin details, electrical charecteristic
For ARM you need to setup the vector table in the reset handler.
You need to locate the vector table at the offset directed by the VTOR register (Vector Table Offset Register)/ VBAR in Arm-A.
When ARM cortex boots up, it expects the first memory pointer by VTOR should be ( SP + reset Handler).
SP will store CPU core's SP and reset vector/handler to its PC.
Reset vector is the address to ISR that the core has to execute.
VTOR has point to a defined location.
We point VTOR to the starting address of Flash Memory (0x0800_0000)
Actually we need to go to APH1 peripheral clock to enable the GPIOA
RCC APB1 clock enable register ( by default all values are 0)
we have to enable some peripheral out of it
- So far we have completed the Enabling of GPIOA
Now we know,
- How to flash a device
- How to enable a peripheral
- Set the Mode bit (in/out)
- Put the data on output data register