32.4 Registers and Bits
| Symbol | Description |
|---|---|
| R/W | Read/Write accessible register bit. The user can read from and write to this bit. |
| R | Read-only accessible register bit. The user can only read this bit. Writes will be ignored. |
| W | Write-only accessible register bit. The user can only write this bit. Reading this bit will return an undefined value. |
| BITFIELD | Bitfield names are shown in uppercase. Example: INTMODE. |
| BITFIELD[n:m] | A set of bits from bit n down to m. Example: PINA[3:0] = {PINA3, PINA2, PINA1, PINA0}. |
| Reserved |
Reserved bits, bit fields, and bit field values are unused and
reserved for future use. For compatibility with future devices, always write
reserved bits to ‘ |
| PERIPHERALn | If several instances of the peripheral exist, the peripheral name is followed by a single number to identify one instance. Example: USARTn is the collection of all instances of the USART module, while USART3 is one specific instance of the USART module. |
| PERIPHERALx | If several instances of the peripheral exist, the peripheral name is followed by a single capital letter (A-Z) to identify one instance. Example: PORTx is the collection of all instances of the PORT module, while PORTB is one specific instance of the PORT module. |
| Reset | Value of a register after a Power-on Reset. This is also the value of registers in a peripheral after performing a software Reset of the peripheral, except for the Debug Control registers. |
| SET/CLR/TGL | Registers with SET/CLR/TGL suffix allow the
user to clear and set bits in a register without doing a read-modify-write
operation. Each SET/CLR/TGL register is paired with the register it is affecting. Both registers in a register pair return the same value when read. Example: In the PORT peripheral, the OUT and OUTSET registers form such a register pair. The contents of OUT will be modified by a write to OUTSET. Reading OUT and OUTSET will return the same value. Writing a ‘ Writing a
‘ Writing a ‘ |