XA-S3 NXP Semiconductors, XA-S3 Datasheet - Page 7
Manufacturer Part Number
The XA-S3 device is a member of Philips Semiconductors? XA(eXtended Architecture) family of high performance 16-bitsingle-chip microcontrollers
2000 Dec 01
P0.0 – P0.7
XA 16-bit microcontroller
32 K/1 K OTP/ROM/ROMless, 8-channel 8-bit A/D, low voltage (2.7 V–5.5 V),
C, 2 UARTs, 16 MB address range
1, 20, 55
2, 21, 54
latched as a 0, external program memory is used exclusively. When latched as a 1, internal
program memory will be used up to its limit, and external program memory used above that
Ground: 0 V reference.
Power Supply: This is the power supply voltage for normal, idle, and power down
Reset: A low on this pin resets the microcontroller, causing I/O ports and peripherals to
take on their default states, and the processor to begin execution at the address contained
in the reset vector.
Reset Output: This pin outputs a low whenever the XA-S3 processor is reset for any
reason. This includes an external reset via the RST pin, watchdog reset, and the RESET
Address Latch Enable/Program Pulse: A high output on the ALE pin signals external
circuitry to latch the address portion of the multiplexed address/data bus. A pulse on ALE
occurs only when it is needed in order to process a bus cycle.
Program Store Enable: The read strobe for external program memory. When the
microcontroller accesses external program memory, PSEN is driven low in order to enable
memory devices. PSEN is only active when external code accesses are performed.
External Access/Bus Wait: The EA input determines whether the internal program
memory of the microcontroller is used for code execution. The value on the EA pin is
latched as the external reset input is released and applies during later execution. When
point. After reset is released, this pin takes on the function of bus WAIT input. If WAIT is
asserted high during an external bus access, that cycle will be extended until WAIT is
Crystal 1: Input to the inverting amplifier used in the oscillator circuit and input to the
internal clock generator circuits.
Crystal 2: Output from the oscillator amplifier.
Clock Output: This pin outputs a buffered version of the internal CPU clock. The clock
output may be used in conjunction with the external bus to synchronize WAIT state
generators, etc. The clock output may be disabled by software.
Analog Power Supply: Positive power supply input for the A/D converter.
A/D Positive Reference Voltage: High end reference for the A/D converter.
A/D Negative Reference Voltage: Low end reference for the A/D converter.
Port 0: Port 0 is an 8-bit I/O port with a user-configurable output type. Port 0 latches have
1s written to them and are configured in the quasi-bidirectional mode during reset. The
operation of port 0 pins as inputs and outputs depends upon the port configuration
selected. Each port pin is configured independently. Refer to the section on I/O port
configuration and the DC Electrical Characteristics for details.
When the external program/data bus is used, Port 0 becomes the multiplexed low
data/instruction byte and address lines 4 through 11.
NAME AND FUNCTION
NAME AND FUNCTION