UM10413
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© NXP B.V. 2011. All rights reserved.
User manual
Rev. 1 — 16 December 2011
69 of 268
NXP Semiconductors
UM10413
MPT612 User manual
IO0DIR is the slow speed GPIO register, while the enhanced GPIO functions are
supported via the register FIO0DIR.
Aside from the 32-bit long and word only accessible register FIODIR, every fast GPIO pins
can also be controlled via several byte and half-word accessible registers listed in
. Next to providing the same functions as register FIODIR, these additional
registers allow easier and faster access to the physical pins.
13.4.2 Fast GPIO mask register (FIOMASK, FIO0MASK - 0x3FFF C010)
This register is available in the enhanced group of registers only. It is used to select pins
that are not affected by a write access to register FIOPIN, FIOSET or FIOCLR. The mask
register also filters out the pin’s content when register FIOPIN is read.
A bit set to logic 0 in this register enables an access to the corresponding physical pin via
a read or write access. If a bit in this register is logic 1, the corresponding pin is not
changed with write access and if read, is not reflected in the updated register FIOPIN. For
software examples, see
Section 13.5 “GPIO usage notes” on page 73
.
Table 67.
GPIO Direction register (IO0DIR - address 0xE002 8008) bit description
Bit
Symbol
Value Description
Reset value
31:0
P0xDIR
slow GPIO direction control bits. Bit 0 controls PIO0 ... bit 30 controls PIO30.
0x0000 0000
0
controlled pin is input
1
controlled pin is output
Table 68.
Fast GPIO direction register (FIO0DIR - address 0x3FFF C000) bit description
Bit
Symbol
Value Description
Reset value
31:0
FP0xDIR
fast GPIO direction control bits. Bit 0 in FIO0DIR controls PIO0 ... Bit 30 in
register FIO0DIR controls PIO30.
0x0000 0000
0
controlled pin is input
1
controlled pin is output
Table 69.
Fast GPIO Direction control byte and half-word accessible register description
Register
name
Register
length (bits)
and access
Address
Description
Reset
value
FIO0DIR0
8 (byte)
0x3FFF C000
fast GPIO direction control register 0. Bit 0 in register FIO0DIR0
corresponds to PIO0 ... bit 7 to PIO7.
0x00
FIO0DIR1
8 (byte)
0x3FFF C001
fast GPIO direction control register 1. Bit 0 in register FIO0DIR1
corresponds to PIO8 ... bit 7 to PIO15.
0x00
FIO0DIR2
8 (byte)
0x3FFF C002
fast GPIO direction control register 2. Bit 0 in register FIO0DIR2
corresponds to PIO16 ... bit 7 to PIO23.
0x00
FIO0DIR3
8 (byte)
0x3FFF C003
fast GPIO direction control register 3. Bit 0 in register FIO0DIR3
corresponds to PIO24 ... bit 7 to PIO31.
0x00
FIO0DIRL
16
(half-word)
0x3FFF C000
fast GPIO direction control lower half-word register. Bit 0 in register
FIO0DIRL corresponds to PIO0 ... bit 15 to PIO15.
0x0000
FIO0DIRU
16
(half-word)
0x3FFF C002
fast GPIO direction control upper half-word register. Bit 0 in register
FIO0DIRU corresponds to PIO16 ... bit 15 to PIO31.
0x0000