System Overview
Am186™CC/CH/CU Microcontrollers User’s Manual
3-21
PROGRAMMABLE I/O (PIOS)
PIO47–PIO0
(For a list of the
multiplexed
signals ordered
by PIO number,
see Table 3-2.)
B
Shared Programmable I/O pins can be programmed with the
following attributes: PIO function (enabled/disabled), direction
(input/output), and weak pullup or pulldown.
After a reset, the PIO pins default to various configurations. Most
of the PIO pins are configured as PIO inputs with pullup after
reset. The system initialization code must reconfigure any PIO
pins as required.
PIO5, PIO15, PIO27, PIO29, PIO30, and PIO33–PIO35 are
capable of generating an interrupt on the shared interrupt
channel 14.
The multiplexed signals PIO8/ARDY, PIO13/PCS0,
PIO14/PCS1, PIO15/WR, PIO29/DT/R, PIO30/DEN,
PIO33/ALE, PIO34/BHE, and PIO35/SRDY default to non-PIO
operation at reset.
The following PIO signals are multiplexed with alternate signals
that can be used by emulators: PIO8, PIO15, PIO33, PIO34, and
PIO35. Consider any emulator requirements for the alternate
signals before using these pins as PIOs.
PROGRAMMABLE TIMERS
[PWD]
[INT8]
PIO6
STI
Pulse-Width Demodulator: If pulse-width demodulation is
enabled, [PWD] processes a signal through the Schmitt trigger
input. [PWD] is used internally to drive [TMRIN0] and [INT8], and
[PWD] is inverted internally to drive [TMRIN1] and an additional
internal interrupt. If interrupts are enabled and Timer 0 and Timer
1 are properly configured, the pulse width of the alternating
[PWD] signal can be calculated by comparing the values in Timer
0 and Timer 1.
In PWD mode, the signals [TMRIN0]/PIO27 and [TMRIN1]/PIO0
can be used as PIOs. If they are not used as PIOs they are
ignored internally.
The additional internal interrupt used in PWD mode uses the
same interrupt channel as [INT7]. If [INT7] is used, it must be
assigned to the shared interrupt channel.
Table 3-7
Signal Descriptions (Continued)
Signal Name
1
Multiplexed
Signal(s)
Type Description
Содержание Am186 CC
Страница 1: ...Am186 CC CH CU Microcontrollers User s Manual Order 21914B...
Страница 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Страница 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Страница 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Страница 39: ...Architectural Overview Am186 CC CH CU Microcontrollers User s Manual 1 15 Figure 1 6 32 Channel Linecard CH CC...
Страница 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Страница 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Страница 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Страница 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Страница 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...