Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Data Sheet
Product codes
AT32UC3A3-XPLD
38
32072H–AVR32–10/2012
AT32UC3A3
5.4
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.
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 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:
0xFFFF5000
TWIS0
Two-wire Slave Interface - TWIS0
0xFFFF5400
TWIS1
Two-wire Slave Interface - TWIS1
Table 5-2.
Peripheral Address Mapping
Table 5-3.
Local Bus Mapped GPIO Registers
Port
Register
Mode
Local Bus
Address
Address
Access
0
Output Driver Enable Register (ODER)
WRITE
0x40000040
Write-only
SET
0x40000044
Write-only
CLEAR
0x40000048
Write-only
TOGGLE
0x4000004C
Write-only
Output Value Register (OVR)
WRITE
0x40000050
Write-only
SET
0x40000054
Write-only
CLEAR
0x40000058
Write-only
TOGGLE
0x4000005C
Write-only
Pin Value Register (PVR)
-
0x40000060
Read-only
1
Output Driver Enable Register (ODER)
WRITE
0x40000140
Write-only
SET
0x40000144
Write-only
CLEAR
0x40000148
Write-only
TOGGLE
0x4000014C
Write-only
Output Value Register (OVR)
WRITE
0x40000150
Write-only
SET
0x40000154
Write-only
CLEAR
0x40000158
Write-only
TOGGLE
0x4000015C
Write-only
Pin Value Register (PVR)
-
0x40000160
Read-only