EM6580SO14A EMMICRO [EM Microelectronic - MARIN SA], EM6580SO14A Datasheet - Page 36

• Manufacturer Part Number: EM6580SO14A
• Description: Ultra Low Power 8-pin Flash Microcontroller
• Manufacturer: EMMICRO [EM Microelectronic - MARIN SA]

R
EM6580
In this case PA[4] input is blocked for all other functions, because its level can be in a zone where logic ‘0’ or ‘1’
are not well defined and this would generate an over consumption otherwise. So it is dedicated only to SVLD
comparator input to be compared with internal band-gap reference. NoPullPA[4] must be set to ‘1’ - Pull-
UP/Down must be removed by register also.
In both cases if V
(V
) or PA[4] level is tested than if selected tested level lower an IRQ can be generated if
bat
dd
enabled.
With SVLDen bit one can switch on the band-gap, resistive divider and Comparator continuously. Like that one
can monitor V
or PA[4] level continuously, at higher frequency (ck[15]). Only at the beginning after setting
bat
the SVLDen at ‘1’ one has to wait until VLDbusy drops to ‘0’ indicating that system is powered up (band-gap
reference and resistor divider are stabilized and comparator is ready to give proper result). This will increase
power consumption by typ. 4цA @ V
=1.5V while used.
dd
During continuously monitoring one can change RegSVLDlev register value on fly and the new result should
be read only after about 1.5 * ck[15] to be sure it is a result of a new SVLDlev selection. Depending on CPUclk
and divisions to obtained SysClk this can be 2 / 6 / 10 / 20 / 36 instruction after RegSVLDlev change for
multiples by 1 / 2 / 4 / 8 / 16.
When fast monitoring is not necessary any more one can remove it by clearing SVLDen to ‘0’.
When SVLD logic is used for this fast monitoring IRQ can also be generated when checked level falls below its
value.
Figure 23. SVLD timing in “ADC” mode when SVLDen set @ “1”
Due to IRQSvld which can come very fast – with ck[15] there is danger that immediately after coming out from
IRQ subroutine new IRQSvld which came during that time put uC back in IRQ subroutine and software can be
stacked at this place until checked input is lower then SVLD level. Otherwise IntEn register must be cleared in
IRQ subroutine already !! or even better to use this function by reading the SVLD result only and not setting the
MaskIRQSvld.
Copyright © 2006, EM Microelectronic-Marin SA
36
www.emmicroelectronic.com