View detail for Migrating from AT89C2051/C4051 to AT89S2051/S4051

View detail for Migrating from AT89C2051/C4051 to AT89S2051/S4051
Migrating from AT89C2051/C4051 to
AT89S2051/S4051
Flash
Microcontrollers
New Features
• 8-bit Pulse-width Modulation
• Enhanced UART Serial Port with Framing Error Detection and Automatic
•
•
•
•
•
•
•
•
•
Address Recognition
On-chip Analog Comparator with Selectable Interrupt
Brown-out Reset
Internal Power-on Reset
Interrupt Recovery from Power-down Mode
Programmable and Fuseable x2 Clock Option
Four-level Enhanced Interrupt Controller
Power-off Flag
Flexible Programming (Byte and Page Mode)
User Serviceable Signature Page (32 Bytes)
Application
Note
1. Introduction
The purpose of this application note is to help users convert existing designs from
AT89C2051/C4051 to AT89S2051/S4051. This application note describes
AT89S2051/S4051 memory sizes, features, and SFR mapping register differences.
More detailed information can be found in the AT89S2051/S4051 datasheet.
2. Memory Sizes
Memory
AT89C2051
AT89C4051
AT89S2051
AT89S4051
Flash
2K Bytes
4K Bytes
2K Bytes
4K Bytes
RAM
128 Bytes
128 Bytes
256 Bytes
256 Bytes
3. 8-bit Pulse-width Modulation
A generated waveform is output on the Timer 1 input pin. Timer 0 acts as an 8-bit
prescaler to select the Pulse-width Modulation base.
3554A–MCU–5/05
4. Enhanced UART Serial Port with Framing Error Detection and Automatic
Address Recognition
When used for frame error detection, the UART looks for missing stop bits in the communication.
A missing bit will set the FE bit in the SCON Register. Automatic Address Recognition allows the
UART to recognize certain addresses in the serial bit stream by using hardware to make the
comparison.
5. On-chip Analog Comparator with Selectable Interrupt
When the positive input AIN0 (P1.0) is greater than the negative input AIN1 (P1.1), the logical
output is 1; otherwise, the output is 0. The comparator can be configured to cause an interrupt
under a variety of output value conditions by setting the CM bits in ACSR in the SFR map. Three
debouncing modes are provided to filter out noise caused by slow-moving analog inputs.
6. Brown-out Reset
When VCC decreases to a value below the trigger level, the Brown-out Reset is immediately activated. The Brown-out Detection ensures the system will enter reset without the possibility of
errors induced by incorrect execution if VCC fails or dips.
When VCC increases above the trigger level, the Brown-out Detector will start the microcontroller
after 2 ms. For the AT89C4051, the Brown-out Detector starts the microcontroller after 15 ms.
7. Internal Power-on Reset
When VCC reaches the Power-on Reset threshold voltage, an internal reset signal is generated.
The Power-on Reset circuit ensures that the device is reset from power-on.
8. Interrupt Recovery from Power-down Mode
An enabled external interrupt (through INT0 or INT1) can be used to exit from the power-down
mode. Two wake-up options are available to exit from power-down mode via interrupt. When bit
CLKREG.2 is 0 following a falling edge on the interrupt input pin, the CPU will resume execution
after a set period of time. When CLKREG.2 is 1, the wake-up mode is externally controlled by
the interrupt pin and the CPU will resume execution after the rising edge of the same pin. In
older derivatives, the only way to recover from the Power-down mode is to perform a hardware
reset.
9. Programmable and Fuseable x2 Clock Option
The x2 clock option allows the microcontroller to execute one machine cycle in 6 clock periods
instead of 12 clock periods. This can be set either through hardware or software.
10. Four-level Enhanced Interrupt Controller
Each interrupt source can be individually programmed to one of four priority levels by setting or
clearing a bit in the Interrupt Priority (IP) register and in the Interrupt Priority High (IPH) register.
11. Power-off Flag
The Power-off Flag is in the PCON register in the SFR map and is set to “1” during power-up
(i.e. cold reset). The Power-off Flag is not affected by External Reset or Brown-out Reset
(i.e. warm resets) and can be used to indicate that the microcontroller has been powered down.
2
Migrating from AT89C2051/C4051 to AT89S2051/S4051
3554A–MCU–5/05
Migrating from AT89C2051/C4051 to AT89S2051/S4051
12. Flexible Programming (Byte and Page Mode)
The program memory can be programmed using the serial ISP interface while RST is strapped
to VCC. Program memory can be programmed in page mode (1 code page = 32 bytes) or byte
mode.
Parallel page mode programming requires that the user load the upper 7 bits of the address
before issuing the read/write command. The XTAL1 pin is used to increment the address for
page read/write.
13. User Serviceable Signature Page (32 Bytes)
Thirty-two bytes are accessible to the user to program their own desired data. Bytes can be programmed by either parallel or serial mode.
14. SFR Mapping
The highlighted SFR locations are new registers for the AT89S2051/S4051 devices.
0F8H
0F0H
0FFH
B
0F7H
0E8H
0E0H
0EFH
ACC
0E7H
0D8H
0D0H
0DFH
PSW
0D7H
0C8H
0CFH
0C0H
0C7H
0B8H
IP
0B0H
P3
0A8H
IE
SADEN
0BFH
IPH
SADDR
0AFH
0A0H
0A7H
98H
SCON
90H
P1
88H
TCON
80H
0B7H
SBUF
9FH
TMOD
TL0
TL1
SP
DPL
DPH
TH0
TH1
ACSR
97H
CLKREG
8FH
PCON
87H
15. Register Differences
Registers and bits in AT89C2051/C4051 and the AT89S051/S4051 equivalents.
AT89C2051/C4051
Register
AT89S2051/S4051
Register
IE
EA -- -- ES ET1 EX1 ET0 EX0
IE
EA EC -- ES ET1 EX1 ET0 EX0
IP
-- -- -- PS PT1 PX1 PT0 PX0
IP
-- PC -- PS PT1 PX1 PT0 PX0
PCON
SMOD -- -- -- GF1 GF0 PD IDL
PCON
SMOD1 SMOD0 PWDEX POF GF1 GF0 PD IDL
SCON
SM0 SM1 SM2 REN TB8 RB8 TI RI
SCON
SM0/FE SM1 SM2 REN TB8 RB8 TI RI
3
3554A–MCU–5/05
Atmel Corporation
2325 Orchard Parkway
San Jose, CA 95131, USA
Tel: 1(408) 441-0311
Fax: 1(408) 487-2600
Regional Headquarters
Europe
Atmel Sarl
Route des Arsenaux 41
Case Postale 80
CH-1705 Fribourg
Switzerland
Tel: (41) 26-426-5555
Fax: (41) 26-426-5500
Asia
Room 1219
Chinachem Golden Plaza
77 Mody Road Tsimshatsui
East Kowloon
Hong Kong
Tel: (852) 2721-9778
Fax: (852) 2722-1369
Japan
9F, Tonetsu Shinkawa Bldg.
1-24-8 Shinkawa
Chuo-ku, Tokyo 104-0033
Japan
Tel: (81) 3-3523-3551
Fax: (81) 3-3523-7581
Atmel Operations
Memory
2325 Orchard Parkway
San Jose, CA 95131, USA
Tel: 1(408) 441-0311
Fax: 1(408) 436-4314
RF/Automotive
Theresienstrasse 2
Postfach 3535
74025 Heilbronn, Germany
Tel: (49) 71-31-67-0
Fax: (49) 71-31-67-2340
Microcontrollers
2325 Orchard Parkway
San Jose, CA 95131, USA
Tel: 1(408) 441-0311
Fax: 1(408) 436-4314
La Chantrerie
BP 70602
44306 Nantes Cedex 3, France
Tel: (33) 2-40-18-18-18
Fax: (33) 2-40-18-19-60
ASIC/ASSP/Smart Cards
1150 East Cheyenne Mtn. Blvd.
Colorado Springs, CO 80906, USA
Tel: 1(719) 576-3300
Fax: 1(719) 540-1759
Biometrics/Imaging/Hi-Rel MPU/
High Speed Converters/RF Datacom
Avenue de Rochepleine
BP 123
38521 Saint-Egreve Cedex, France
Tel: (33) 4-76-58-30-00
Fax: (33) 4-76-58-34-80
Zone Industrielle
13106 Rousset Cedex, France
Tel: (33) 4-42-53-60-00
Fax: (33) 4-42-53-60-01
1150 East Cheyenne Mtn. Blvd.
Colorado Springs, CO 80906, USA
Tel: 1(719) 576-3300
Fax: 1(719) 540-1759
Scottish Enterprise Technology Park
Maxwell Building
East Kilbride G75 0QR, Scotland
Tel: (44) 1355-803-000
Fax: (44) 1355-242-743
Literature Requests
www.atmel.com/literature
Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any
intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN ATMEL’S TERMS AND CONDITIONS OF SALE LOCATED ON ATMEL’S WEB SITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY
WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT
OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no
representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications
and product descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Atmel’s products are not
intended, authorized, or warranted for use as components in applications intended to support or sustain life.
© Atmel Corporation 2005. All rights reserved. Atmel®, logo and combinations thereof, Everywhere You Are ® and others, are
registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others.
Printed on recycled paper.
3554A–MCU–5/05
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement