saa1575hl NXP Semiconductors, saa1575hl Datasheet - Page 9

• Manufacturer Part Number: saa1575hl
• Description: Global Positioning System Gps Baseband Processor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
1999 Jun 04
V
DMCS
PWRFAIL
XTAL4
XTAL3
PWRB
PWRM
V
V
TXD1
RXD1
TXD0
RXD0
V
V
GPIO4
GPIO3
RFDAT
RFCLK
SYMBOL
CC(R)
SS
CC(B)
SS
CC(P)
Global Positioning System (GPS)
baseband processor
PIN
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
I/O
I/O
I/O
O
O
O
O
O
O
O
O
I
I
I
I
Backup core power supply: 2.4 to 3.6 V only. Separate from the core supply to allow
a low capacity battery to be used to maintain the Real-Time Clock (RTC) function.
This should be powered from the main supply during normal operation and switched
to battery backup when the main supply fails.
External data memory select: external RAM select pin, active LOW when the
external data memory space is addressed. This output is driven from V
V
Power fail indicator: a LOW on this pin forces the embedded microcontroller into
reset. Reset will not be de-asserted until a set time after both PWRDN and PWRFAIL
go HIGH. For correct start-up, this pin should be LOW on power-up.
Crystal 4: output from the RTC oscillator amplifier; this pin is only 3 V tolerant
Crystal 3: input to inverting amplifier used in the RTC oscillator circuits (32.768 kHz);
this pin is only 3 V tolerant
Backup supply select: this output is intended to drive an external FET used to switch
the battery backup supply(s). It is active LOW and is controlled directly by the
PWRFAIL.
Main supply select: this output is intended to drive an external FET used to switch
the main supply(s). It is active LOW and is controlled directly by PWRFAIL.
Ground: 0 V reference
Backup I/O power supply: 2.4 to 5.5 V only. Supply for the RAM select, power fail
and power switching I/O pads only allowing these functions to be powered when the
main power supply fails. This should be powered from the main supply during normal
operation and switched to battery backup when the main supply fails.
Transmitter output 1: transmit channel for serial port 1 (UART1) of the embedded
processor
Receiver input 1: receive channel for serial port 1 (UART1) of the embedded
processor. It is intended that this serial port is dedicated to differential GPS
information (dependent on firmware).
Transmitter output 0: transmit channel for serial port 0 (UART0) of the embedded
processor.
Receiver input 0: receive channel for serial port 0 (UART0) of the embedded
processor. It is intended that this serial port is dedicated to the NMEA data stream
(dependent on firmware).
Ground: 0 V reference
Main I/O power supply: 2.7 to 5.5 V operating range; main supply for the periphery
in normal operation
GPIO bit 4: standard general purpose I/O mapped into the segment 15 of the address
space. The top 4 bits can be used as the XA external timer control access pins
(T0, T1, T2 and T2EX).
GPIO bit 3: standard general purpose I/O mapped into the segment 15 of the address
space. The top 4 bits can be used as the XA external timer control access pins
(T0, T1, T2 and T2EX).
RFIC set-up data: serial data output used to set up the UAA1570HL front-end IC.
RFIC set-up data: clock output for the serial data output used to set up the
UAA1570HL front-end IC. The state of the RFDAT and RFLE lines is latched into the
front-end IC on the rising edge.
CC(B)
supplies to ensure that the external RAM is not enabled during power-down.
9
DESCRIPTION
SAA1575HL
Product specification
CC(R)
and