 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
EM6617 Datasheet(PDF) 18 Page - EM Microelectronic - MARIN SA |
|
||||||||||||||||||||||||||||||
EM6617 Datasheet(HTML) 18 Page - EM Microelectronic - MARIN SA |
|
|
18 / 65 page  EM6617 Copyright © 2005, EM Microelectronic-Marin SA 18 www.emmicroelectronic.com 7.4.2 Pull-up or Pull-down On each terminal of PB[3:0] an internal input pull-up (metal mask MPBPU[n]) or pull-down (metal mask MPBPD[n]) resistor can be connected per metal mask option. Per default the two resistors are in place. In this case one can chose per software to have either a pull-up, a pull-down or no resistor. See below. For Metal mask selection and available resistor values refer to 19.1.2. Pull-down ON : MPBPD[n] must be in place , AND bit NoPdPB[n] must be ‘0’ . Pull-down OFF: MPBPD[n] is not in place, OR if MPBPD[n] is in place NoPdPB[n] = ‘1’ cuts off the pull-down. OR selecting NchOpDPB[n] = ‘1’ cuts off the pull-down. Pull-up ON : MPBPU[n] must be in place, AND bit NchOpDPB[n] must be ‘1’ , AND (bit PBIOCntl[n] = ‘0’ (input mode) OR if PBIOCntl[n] = ‘1’ while PBData[n] = 1. ) Pull-up OFF : MPBPU[n] is not in place, OR if MPBPU[n] is in place NchOpDPB[n] = ‘0’ cuts off the pull-up, OR if MPBPU[n] is in place and if NchOpDPB[n] = ‘1’ then PBData[n] = 0 cuts the pull-up. Never pull-up and pull-down can be active at the same time. For POWER SAVING one can switch off the port B pull resistors between two read phases. No cross current flows in the input amplifier while the port B is not read. The recommended order is : • Switch on the pull resistor. • Allow sufficient time - RC constant - for the pull resistor to drive the line to either VSS or VDD. • Read the port B • Switch off the pull resistor Minimum time with current on the pull resistor is 4 system clock periods, if the RC time constant is lower than 1 system clock period. Adding a NOP instruction before reading moves the number of periods with current in the pull resistor to 6 and the maximum RC delay to 3 clock periods. 7.4.3 CMOS or Nch. Output The port B outputs can be configured as either CMOS or Nch. open drain outputs. In CMOS both logic ‘1’ and ‘0’ are driven out on the terminal. In Nch. Open Drain only the logic ‘0’ is driven on the terminal, the logic ‘1’ value is defined by the internal pull-up resistor (if implemented), or high impedance. Figure 14. CMOS or Nch. Open Drain Outputs I / O Te r m in a l PB [n ] MU X A c tiv e P u ll- u p fo r H igh S tate P B D ata [n] F r eque nc y O u tputs T r i-S tate O u tp ut B u f fer : H igh Im pedan c e fo r Da ta = 1 I / O Te r m in a l PB [n ] MU X P B D a ta [n ] F r eque nc y O u tputs T r i-S tate O u tp ut B u f fer : c lo s ed Da ta 1 C M OS Ou tp u t N c h. O p en D ra in O u tp ut |
Similar Part No. - EM6617 |
|
Similar Description - EM6617 |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
