Zakładka z wyszukiwarką danych komponentów
  Polish  ▼

Delete All
ON OFF
ALLDATASHEET.PL

X  

Preview PDF Download HTML

ATmega16-16PU Arkusz danych(PDF) 52 Page - ATMEL Corporation

Numer części ATmega16-16PU
Szczegółowy opis  8-bit Microcontroller with 16K Bytes In-Syustem Programmable Flash
Download  357 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Producent  ATMEL [ATMEL Corporation]
Strona internetowa  http://www.atmel.com
Logo ATMEL - ATMEL Corporation

ATmega16-16PU Arkusz danych(HTML) 52 Page - ATMEL Corporation

Back Button ATmega16-16PU Datasheet HTML 48Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 49Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 50Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 51Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 52Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 53Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 54Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 55Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 56Page - ATMEL Corporation Next Button
Zoom Inzoom in Zoom Outzoom out
 52 / 357 page
background image
52
2466S–AVR–05/09
ATmega16(L)
Switching between input with pull-up and output low generates the same problem. The user
must use either the tri-state ({DDxn, PORTxn} = 0b00) or the output high state ({DDxn, PORTxn}
= 0b11) as an intermediate step.
Table 20 summarizes the control signals for the pin value.
Reading the Pin Value
Independent of the setting of Data Direction bit DDxn, the port pin can be read through the
PINxn Register bit. As shown in Figure 23, the PINxn Register bit and the preceding latch consti-
tute a synchronizer. This is needed to avoid metastability if the physical pin changes value near
the edge of the internal clock, but it also introduces a delay. Figure 24 shows a timing diagram of
the synchronization when reading an externally applied pin value. The maximum and minimum
propagation delays are denoted t
pd,max and tpd,min respectively.
Figure 24. Synchronization when Reading an Externally Applied Pin Value
Consider the clock period starting shortly after the first falling edge of the system clock. The latch
is closed when the clock is low, and goes transparent when the clock is high, as indicated by the
shaded region of the “SYNC LATCH” signal. The signal value is latched when the system clock
goes low. It is clocked into the PINxn Register at the succeeding positive clock edge. As
indicated by the two arrows t
pd,max and tpd,min, a single signal transition on the pin will be delayed
between ½ and 1½ system clock period depending upon the time of assertion.
Table 20. Port Pin Configurations
DDxn
PORTxn
PUD
(in SFIOR)
I/O
Pull-up
Comment
0
0
X
Input
No
Tri-state (Hi-Z)
0
1
0
Input
Yes
Pxn will source current if ext. pulled
low.
0
1
1
Input
No
Tri-state (Hi-Z)
1
0
X
Output
No
Output Low (Sink)
1
1
X
Output
No
Output High (Source)
SYSTEM CLK
INSTRUCTIONS
SYNC LATCH
PINxn
r17
in r17, PINx
0xFF
0x00
tpd, max
XXX
XXX
tpd, min


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42  43  44  45  46  47  48  49  50  51  52  53  54  55  56  57  58  59  60  61  62  63  64  65  66  67  68  69  70  71  72  73  74  75  76  77  78  79  80  81  82  83  84  85  86  87  88  89  90  91  92  93  94  95  96  97  98  99  100   ...More


Arkusz danych Pobierz

Go To PDF Page


Link URL




Polityka prywatności
ALLDATASHEET.PL
Czy Alldatasheet okazała się pomocna?  [ DONATE ] 

O Alldatasheet   |   Reklama   |   Kontakt   |   Polityka prywatności   |   Linki   |   Lista producentów
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
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