PR31700 Datasheet, PDF (10/36 Pages) NXP Semiconductors – 32-bit RISC microprocessor

Philips Semiconductors
32-bit RISC microprocessor
Preliminary specification
PR31700
NAME
I/O
Power Supply Pins
ONBUTN
I
PWRCS
O
PWROK
I
PWRINT
I
VCC3
I
FUNCTIONS
This pin is used as the On Button for the system. Asserting this signal will cause PWRCS to set to indicate
to the System Power Supply to turn power on to the system. PWRCS will not assert if the PWROK signal is
low.
This pin is used as the chip select for the System Power Supply. When the system is off, the assertion of
this signal will cause the System Power Supply to turn VCCDRAM[[ and VCC3 on to power up the system.
The Power Supply will latch SPI commands on the falling edge of PWRCS.
This pin provides a status from the System Power Supply that there is a good source of power in the
system. This signal typically will be asserted if there is a Battery Charger supplying current or if the Main
Battery is good and the Battery Door is closed. If PWROK is low when the system is powered off, PWRCS
will not assert as a result of the user pressing the ONBUTN or an interrupt attempting to wake up the
system. If the device is on when the PWROK signal goes low, the software will immediately shut down the
system since power is about to be lost. When PWROK goes low, there must be ample warning so that the
software can shut down the system before power is actually lost.
This pin is used by the System Power Supply to alert the software that some status has changed in the
System Power Supply and the software should read the status from the System Power Supply to find out
what has changed. These will be low priority events, unlike the PWROK status, which is a high priority
emergency case.
This pin provides the status of the power supply for the ROM, UCB1200, system buffers, and other transient
components in the system. This signal will be asserted by the System Power Supply when PWRCS is
asserted, and will always be turned off when the system is powered down.
[[V_CCDRAM: This signal provides power for the DRAM and/or SDRAM. The supply must be off when VSTANDBY is first asserted, andremain
off until the system is powered up by the assertion of PWRCS. When the software subsequently powers down the system it may choose to keep
this supply on to preserve the contents of memory.
NAME
SIB Pins
SIBDIN
SIBDOUT
SIBSCLK
SIBSYNC
SIBIRQ
SIBMCLK
I/O
FUNCTIONS
I
This pin contains the input data shifted from UCB1200 and/or external codec device.
O
This pin contains the output data shifted to UCB1200 and/or external codec device.
O
This pin is the serial clock sent to UCB1200 and/or external codec device. The programmable SIBSCLK
rate is derived by dividing down from SIBMCLK.
O
This pin is the frame synchronization signal sent to UCB1200 and/or external codec device. This frame
sync is asserted for one clock cycle immediately before each frame starts and all devices connected to the
SIB monitor SIBSYNC to determine when they should transmit or receive data.
I
This pin is a general purpose input port used for the SIB interrupt source from UCB1200. This interrupt
source can be configured to generate an interrupt on either a positive and/or negative edge.
I/O
This pin is the master clock source for the SIB logic. This pin is available for use in one of two modes. First,
SIBMCLK can be configured as a high-rate output master clock source required by certain external codec
devices. In this mode all SIB clocks are synchronously slaved to the main PR31700 system clock CLK2X.
Conversely, SIBMCLK can be configured as an input slave clock source. In this mode, all SIB clocks are
derived from an external SIBMCLK oscillator source, which is asynchronous with respect to CLK2X. Also,
for this mode, SIBMCLK can still be optionally used as a high-rate master clock source required by certain
external codec devices.
NAME
SPI Pins
SPICLK
SPIOUT
SPIIN
I/O
FUNCTIONS
O
This pin is used to clock data in and out of the SPI slave device.
O
This pin contains the data that is shifted into the SPI slave device.
I
This pin contains the data that is shifted out of the SPI slave device.
NAME
I/O
UART and IR Pins
TXD
O
RXD
I
1998 May 13
FUNCTIONS
This pin is the UART transmit signal from the UART A module.
This pin is the UART receive signal to the UART A module.
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