Programmable Input/Output
23-4
Élan™SC520 Microcontroller User’s Manual
23.4
REGISTERS
A summary listing of the memory-mapped configuration registers used to control the PIO
signals is shown in Table 23-2.
23.5
OPERATION
All PIO signal pins can be programmed as inputs, outputs, or to support their interface
function (e.g., GP bus signals). They are enabled as PIO inputs at power-on reset, with
built-in pullup or pulldown resistors.
As inputs, PIOs are used by software to monitor signals from other devices. They provide
a path to bring signals into the chip that are not available through the other interfaces.
As outputs, the PIOs provide the ability for software to control external devices with signals
that can be driven High or Low.
Table 23-2
PIO Registers—Memory-Mapped
Register
Mnemonic
MMCR
Offset
Address
Function
PIO15–PIO0 Pin Function
Select
PIOPFS15_0
C20h
PIO15–PIO0 or interface function select:
GPIRQ10–GPIRQ8, GPDACK3–GPDACK0,
GPDRQ3–GPDRQ3, GPTC, GPAEN, GPRDY,
GPBHE, GPALE
PIO31–PIO16 Pin Function
Select
PIOPFS31_16
C22h
PIO31–PIO16 or interface function select: RIN2,
DCD2, DSR2, CTS2, GPCS0, GPMEMCS16,
GPIOCS16, GPDBUFOE, GPIRQ7–GPIRQ0
Chip Select Pin Function
Select
CSPFS
C24h
GPCS7–GPCS1 or alternate function select:
TMROUTx, TMRINx, PITGATE2, ROMCS2,
ROMCS1
Clock Select
CLKSEL
C26h
CLKTIMER[CLKTEST] pin enable, clock output
select options (18.432 MHz or 1.8432 MHz
UART, PLL1, PLL2, PIT, and RTC), CLKTIMER
or CLKTEST select
Drive Strength Control
DSCTL
C28h
I/O pad drive strength for SCS3–SCS0,
SRASA–SRASB, SCASA–SCASB, SWEA–
SWEB, SDQM3–SDQM0, MA12–MA0, MD31–
MD0, MECC6–MECC0.
PIO15–PIO0 Direction
PIODIR15_0
C2Ah
PIO15–PIO0 as input or output
PIO31–PIO16 Direction
PIODIR31_16
C2Ch
PIO31–PIO16 as input or output
PIO15–PIO0 Data
PIODATA15_0
C30h
Read/write directly the state of the PIO15–PIO0
pin
PIO31–PIO16 Data
PIODATA31_16
C32h
Read/write directly the state of the PIO31–
PIO16 pin
PIO15–PIO0 Set
PIOSET15_0
C34h
Drive PIO15–PIO0 output High
PIO31–PIO16 Set
PIOSET31_16
C36h
Drive PIO31–PIO16 output High
PIO15–PIO0 Clear
PIOCLR15_0
C38h
Drive PIO15–PIO0 output Low
PIO31–PIO16 Clear
PIOCLR31_16
C3Ah
Drive PIO31–PIO16 output Low
Содержание Elan SC520
Страница 1: ...lan SC520 Microcontroller User s Manual Order 22004A...
Страница 4: ...iv lan SC520 Microcontroller User s Manual...
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Страница 42: ...Architectural Overview 1 14 lan SC520 Microcontroller User s Manual...
Страница 78: ...System Initialization 3 22 lan SC520 Microcontroller User s Manual...
Страница 108: ...Clock Generation and Control 5 10 lan SC520 Microcontroller User s Manual...
Страница 118: ...Reset Generation 6 10 lan SC520 Microcontroller User s Manual...
Страница 148: ...System Arbitration 8 24 lan SC520 Microcontroller User s Manual...
Страница 214: ...SDRAM Controller 10 36 lan SC520 Microcontroller User s Manual...
Страница 230: ...Write Buffer and Read Buffer 11 16 lan SC520 Microcontroller User s Manual...
Страница 288: ...GP Bus DMA Controller 14 22 lan SC520 Microcontroller User s Manual...
Страница 316: ...Programmable Interval Timer 16 8 lan SC520 Microcontroller User s Manual...
Страница 328: ...Software Timer 18 4 lan SC520 Microcontroller User s Manual...
Страница 346: ...Real Time Clock 20 12 lan SC520 Microcontroller User s Manual...
Страница 360: ...UART Serial Ports 21 14 lan SC520 Microcontroller User s Manual...
Страница 414: ...AMDebug Technology 26 8 lan SC520 Microcontroller User s Manual...