AM186ES Advanced Micro Devices, AM186ES Datasheet - Page 164

• Manufacturer Part Number: AM186ES
• Description: microcontrollers provide a low-cost/ high-performance solution for embedded system designers who wish to use the x86 architecture.
• Manufacturer: Advanced Micro Devices

11.3
11.3.1
11.3.2
11-4
Figure 11-4
15
PIO DIRECTION REGISTERS
Each PIO is individually programmed as an input or output by a bit in one of the PIO Direction
registers (see Figure 11-4 and Figure 11-5). Table 11-2 on page 11-3 shows the values
that the PIO mode bits and the PIO direction bits can encode. The column titled Power-On
Reset Status in Table 11-1 lists the reset default values for the PIOs. Bits in the PIO Direction
registers have the same correspondence to pins as bits in the PIO Mode registers.
PIO Direction 1 Register
(PDIR1, Offset 78h)
The value of PDIR1 at reset is FFFFh.
Bits 15–0: PIO Direction Bits (PDIR31–PDIR16)—This field determines whether each
PIO pin acts as an input or an output. The most significant bit of the PDIR field determines
the direction of PIO31, the next bit determines the direction of PIO30, and so on. A 1 in the
bit configures the PIO signal as an input and a 0 in the bit configures it as an output or as
normal pin function.
PIO Direction 0 Register
(PDIR0, Offset 72h)
The value of PDIR0 at reset is FC0Fh.
Bits 15–0: PIO Direction Bits (PDIR15–PDIR0)—This field is a continuation of the PDIR
field in the PIO Direction 1 register.
(PDIR1, offset 78h)
PIO Direction 1 Register
PDIR (31–16)
7
Programmable I/O Pins
0
Figure 11-5
15
(PDIR0, offset 72h)
PIO Direction 0 Register
PDIR (15–0)
7
0