Datasheet
177
AT32UC3A
22.5.1 Access Types
Each configuration register can be accessed in four different ways. The first address location
can be used to write the register directly. This address can also be used to read the register
value. The following addresses facilitate three different types of write access to the register. Per-
forming a “set” access, all bits written to ‘1’ will be set. Bits written to ‘0’ will be unchanged by the
operation. Performing a “clear” access, all bits written to ‘1’ will be cleared. Bits written to ‘0’ will
be unchanged by the operation. Finally, a toggle access will toggle the value of all bits written to
‘1’. Again all bits written to ‘0’ remain unchanged. Note that for some registers (e.g. IFR), not all
access methods are permitted.
Note that for ports with less than 32 bits, the corresponding control registers will have unused
bits. This is also the case for features that are not implemented for a specific pin. Writing to an
unused bit will have no effect. Reading unused bits will always return 0.
0xA0 Interrupt Mode Register 0 Read/Write IMR0 Read/Write 0x00000000
0xA4 Interrupt Mode Register 0 Set IMR0S Write-Only
0xA8 Interrupt Mode Register 0 Clear IMR0C Write-Only
0xAC Interrupt Mode Register 0 Toggle IMR0T Write-Only
0xB0 Interrupt Mode Register 1 Read/Write IMR1 Read/Write 0x00000000
0xB4 Interrupt Mode Register 1 Set IMR1S Write-Only
0xB8 Interrupt Mode Register 1 Clear IMR1C Write-Only
0xBC Interrupt Mode Register 1 Toggle IMR1T Write-Only
0xC0 Glitch Filter Enable Register Read/Write GFER Read/Write
1b for each
implemented
GPIO pin in port
0xC4 Glitch Filter Enable Register Set GFERS Write-Only
0xC8 Glitch Filter Enable Register Clear GFERC Write-Only
0xCC Glitch Filter Enable Register Toggle GFERT Write-Only
0xD0 Interrupt Flag Register Read IFR Read-Only 0x00000000
0xD4 Interrupt Flag Register - - -
0xD8 Interrupt Flag Register Clear IFRC Write-Only
0xDC Interrupt Flag Register - - -
0xE0-
0xFF
RESERVED - - -
Table 22-2. GPIO Register Map
Offset Register Function Name Access Reset value
32058K
AVR32-01/12