Zakładka z wyszukiwarką danych komponentów
  Polish  ▼

Delete All
ON OFF
ALLDATASHEET.PL

X  

Preview PDF Download HTML

ATmega16-16PU Arkusz danych(PDF) 92 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) 92 Page - ATMEL Corporation

Back Button ATmega16-16PU Datasheet HTML 88Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 89Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 90Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 91Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 92Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 93Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 94Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 95Page - ATMEL Corporation ATmega16-16PU Datasheet HTML 96Page - ATMEL Corporation Next Button
Zoom Inzoom in Zoom Outzoom out
 92 / 357 page
background image
92
2466S–AVR–05/09
ATmega16(L)
Accessing 16-bit
Registers
The TCNT1, OCR1A/B, and ICR1 are 16-bit registers that can be accessed by the AVR CPU via
the 8-bit data bus. The 16-bit register must be byte accessed using two read or write operations.
Each 16-bit timer has a single 8-bit register for temporary storing of the High byte of the 16-bit
access. The same temporary register is shared between all 16-bit registers within each 16-bit
timer. Accessing the Low byte triggers the 16-bit read or write operation. When the Low byte of a
16-bit register is written by the CPU, the High byte stored in the temporary register, and the Low
byte written are both copied into the 16-bit register in the same clock cycle. When the Low byte
of a 16-bit register is read by the CPU, the High byte of the 16-bit register is copied into the tem-
porary register in the same clock cycle as the Low byte is read.
Not all 16-bit accesses uses the temporary register for the High byte. Reading the OCR1A/B 16-
bit registers does not involve using the temporary register.
To do a 16-bit write, the High byte must be written before the Low byte. For a 16-bit read, the
Low byte must be read before the High byte.
The following code examples show how to access the 16-bit Timer Registers assuming that no
interrupts updates the temporary register. The same principle can be used directly for accessing
the OCR1A/B and ICR1 Registers. Note that when using “C”, the compiler handles the 16-bit
access.
Note:
1. See “About Code Examples” on page 7.
The assembly code example returns the TCNT1 value in the r17:r16 register pair.
It is important to notice that accessing 16-bit registers are atomic operations. If an interrupt
occurs between the two instructions accessing the 16-bit register, and the interrupt code
updates the temporary register by accessing the same or any other of the 16-bit Timer Regis-
ters, then the result of the access outside the interrupt will be corrupted. Therefore, when both
the main code and the interrupt code update the temporary register, the main code must disable
the interrupts during the 16-bit access.
Assembly Code Example(1)
...
; Set TCNT1 to 0x01FF
ldi
r17,0x01
ldi
r16,0xFF
out
TCNT1H,r17
out
TCNT1L,r16
; Read TCNT1 into r17:r16
in
r16,TCNT1L
in
r17,TCNT1H
...
C Code Example
(1)
unsigned int
i;
...
/* Set TCNT1 to 0x01FF */
TCNT
1 = 0x1FF;
/* Read TCNT1 into i */
i = TCNT1;
...


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