IDT 89HPES16T4G2, Preliminary User'S Manual

Page: 134 / 149

IDT Configuration Registers
PES16T4G2 User Manual 8 - 56 January 28, 2013
Notes
GPIOFUNC - General Purpose I/O Control Function (0x418)
GPIOCFG - General Purpose I/O Configuration (0x41C)
GPIOD - General Purpose I/O Data (0x420)
23:16 PWR2RST RW 0x14
Sticky
Slot Power to Reset Negation. This field contains the delay from
stable downstream port power to negation of the downstream port
reset in units of 10 mS. A value of zero corresponds to no delay.
This field may be used to meet the T
PCPERL
specification.
The default value corresponds to 200 mS.
31:24 RST2PWR RW 0x14
Sticky
Reset Negation. This field contains the delay from negation of a
downstream port’s reset to disabling of a downstream port’s power
in units of 10 mS. A value of zero corresponds to no delay.
The default value corresponds to 200 mS.
Bit
Field
Field
Name
Type Default
Value
Description
15:0 GPIOFUNC RW 0x0
Sticky
GPIO Function. Each bit in this field controls the corresponding
GPIO pin. When set to a one, the corresponding GPIO pin oper-
ates as the alternate function as defined in Table 4.1 of Chapter 4.
When a bit is cleared to a zero, the corresponding GPIO pin oper-
ates as a general purpose I/O pin.
31:16 Reserved RO 0x0 Reserved field.
Bit
Field
Field
Name
Type Default
Value
Description
15:0 GPIOCFG RW 0x0
Sticky
GPIO Configuration. Each bit in this field controls the correspond-
ing GPIO pin. When a bit is configured as a general purpose I/O
pin and the corresponding bit in this field is set, then the pin is con-
figured as a GPIO output. When a bit is configured as a general
purpose I/O pin and the corresponding bit in this field is zero, then
the pin is configured as an input. When the pin is configured as an
alternate function, the behavior of the pin is defined by the alter-
nate function.
31:16 Reserved RO 0x0 Reserved field.
Bit
Field
Field
Name
Type Default
Value
Description
15:0 GPIOD RW HWINIT
Sticky
GPIO Data. Each bit in this field controls the corresponding GPIO
pin. Reading this field returns the current value of each GPIO pin
regardless of GPIO pin mode (i.e., alternate function or GPIO pin).
Writing a value to this field causes the corresponding pins which
are configured as GPIO outputs to change state to the value writ-
ten.
31:16 Reserved RO 0x0 Reserved field.
Bit
Field
Field
Name
Type Default
Value
Description