Datasheet

33
32059L–AVR32–01/2012
AT32UC3B
7.4 CPU Local Bus Mapping
Some of the registers in the GPIO module are mapped onto the CPU local bus, in addition to
being mapped on the Peripheral Bus. These registers can therefore be reached both by
accesses on the Peripheral Bus, and by accesses on the local bus.
Mapping these registers on the local bus allows cycle-deterministic toggling of GPIO pins since
the CPU and GPIO are the only modules connected to this bus. Also, since the local bus runs at
CPU speed, one write or read operation can be performed per clock cycle to the local bus-
mapped GPIO registers.
The following GPIO registers are mapped on the local bus:
0xFFFF3C00
ADC Analog to Digital Converter - ADC
0xFFFF4000
ABDAC Audio Bitstream DAC - ABDAC
Table 7-2. Peripheral Address Mapping
Table 7-3. Local bus mapped GPIO registers
Port Register Mode
Local Bus
Address Access
0 Output Driver Enable Register (ODER) WRITE 0x4000_0040 Write-only
SET 0x4000_0044 Write-only
CLEAR 0x4000_0048 Write-only
TOGGLE 0x4000_004C Write-only
Output Value Register (OVR) WRITE 0x4000_0050 Write-only
SET 0x4000_0054 Write-only
CLEAR 0x4000_0058 Write-only
TOGGLE 0x4000_005C Write-only
Pin Value Register (PVR) - 0x4000_0060 Read-only
1 Output Driver Enable Register (ODER) WRITE 0x4000_0140 Write-only
SET 0x4000_0144 Write-only
CLEAR 0x4000_0148 Write-only
TOGGLE 0x4000_014C Write-only
Output Value Register (OVR) WRITE 0x4000_0150 Write-only
SET 0x4000_0154 Write-only
CLEAR 0x4000_0158 Write-only
TOGGLE 0x4000_015C Write-only
Pin Value Register (PVR) - 0x4000_0160 Read-only