Z8FS040 datasheet(19/56 Pages) ZILOG

19 / 56 page

ZMOTION

TM Detection and Control Family

Product Specification

PS028506-1110

PRELIMINARY

UART

8 Pin Device: /CTS0 is configured as ANA2 to support the signal input from the Pyroelectric

sensor. It is therefore not available to the user application. The UART is still able to function

correctly without /CTS when CTSE in the U0CTL0 register set to 0.

20 Pin Device: All external UART functions are available for the user application.

28 Pin Device: All external UART functions are available for the user application.

Oscillator Control

All devices can be operated with the internal 5.54 MHz IPO. For applications that require more

processing power or a more accurate time base, an external crystal oscillator or ceramic

resonator may be used.

For the 8 pin device external oscillator support is limited to single pyro mode only since ANA3

(ADC input for second pyro sensor) is multiplexed with Xout. The 20 and 28 pin devices can

be operated with an external oscillator in both single and dual pyro modes.

Do not operate at frequencies lower than the IPO frequency while the PIR engine is enabled or

motion detection performance will be degraded.

No other changes or limitations are placed on these functions by the PIR engine.

Flash Memory

The control registers associated with the Flash memory are all available to the application.

Zilog’s PIR technolgoy uses the value programmed into the Flash Frequency registers

(FFREQ) to determine its required sample timing. This register must be programmed prior to

initializing the PIR engine. The Flash Frequency High (FFREQH) and Flash Frequency Low

Byte (FFREQL) registers combine to form a 16-bit value FFREQ. This value is also used by

the PIR engine to calculate the required sample rate of the ADC and other functions. The 16-

bit value for FFREQ is the System Clock Frequency in KHz and is calculated using the

following equation.

FFREQ[15:0] = {FFREQH[7:0],FFREQL[7:0]} = (System Clock Frequency)/1000

Interrupt Controller

No changes or limitations are placed on the interrupt controller functions by Zilog’s PIR

technology.

Temperature Sensor

The temperature sensor is not tested or calibrated (trim bits are not available). Therefore this

peripheral is not available on any of the Z8FS040 devices.

Z8FS040 Datasheet(PDF) 19 Page - Zilog, Inc.