Tips and tricks/de - Revision history

Stefanhamburg at 11:49, 19 February 2013

2013-02-19T11:49:00Z

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2013-02-15T19:06:43Z

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Admin: Created page with "This section describes tips and tricks received from users. Kyle Kronyak&nbs..."

2013-02-13T10:01:13Z

Created page with "This section describes tips and tricks received from users. Kyle Kronyak&nbs..."

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== (**COPIED FROM ENGLISH PAGE**) ==This section describes tips and tricks received from users.

 

 

Kyle Kronyak : Using all the RAM from an external RAM chip.

 

I have found a way to use the 607 bytes of external SRAM that are normally not available when using hardware SRAM support with BASCOM-AVR. It's actually quite simple. Basically the user just has to disconnect A15 from /CE on the SRAM module, and tie /CE to ground. This makes the chip enabled all the time. Addresses 1-32768 will then be available! The reason is because normally when going above 32768, the A15 pin would go high, disabling the chip. When A15 is not connected to /CE, the chip is always enabled, and allows the address number to "roll over". Therefore address 32162 is actually 0, 32163 is actually 1, 32164 is actually 2, etc. I have only tested this on a 32k SRAM chip. It definitely won't work on a 64k chip, and I believe it already works on any chip below 32k without modification of the circuit.

 

 

Programming problems

 

- When you have unreliable results, use a shielded LPT cable

 

- The AVR chips have a bug, if the erase is not complete. It tend's to hang at some point. Sometimes although the system reports erased but blank check report "not empty". As per Atmel Data Errata You must drop the vcc by 0.5V ( a diode 1N4148 in Series ) if the erase is not happening. ( Such Chip's are unreliable and hence can be used only if you are sure ). This can happen after you have programmed the chip many times.

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[[Category:BASCOM Language Fundamentals/de]]

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-== (**COPIED FROM ENGLISH PAGE**) ==This section describes tips and tricks received from users.
+Dieser Abschnitt enthält Tipps und Tricks von BASCOM-Anwendern.
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-Kyle Kronyak&nbsp;: Using all the RAM from an external RAM chip.
+Kyle Kronyak&nbsp;: Benutzung des kompletten RAM eines externen RAM Chips.
 <span style="font-family: Arial;">&nbsp;</span>
-I have found a way to use the 607 bytes of external SRAM that are normally not available when using hardware SRAM support with BASCOM-AVR. It's actually quite simple. Basically the user just has to disconnect A15 from /CE on the SRAM module, and tie /CE to ground. This makes the chip enabled all the time. Addresses 1-32768 will then be available! The reason is because normally when going above 32768, the A15 pin would go high, disabling the chip. When A15 is not connected to /CE, the chip is always enabled, and allows the address number to "roll over". Therefore address 32162 is actually 0, 32163 is actually 1, 32164 is actually 2, etc. I have only tested this on a 32k SRAM chip. It definitely won't work on a 64k chip, and I believe it already works on any chip below 32k without modification of the circuit.
+Ich habe einen Weg gefunden, die kompletten 607 Byte externen RAM zu nutzen welche normalerweise nicht verfügbar sind bei Nutzung des BASCOM SRAM-Supports. Es ist sehr einfach. Man muss nur A15 von /CE des RAM-Moduls und /CE mit Gnd verbinden. Dadurch ist der Chip ständig enabled. Die Adressen 1-32768 sind dann verfügbar! Der Hintergrund ist, dass der A15 Pin normalerweise auf High geht wenn man über 32768 geht. Wenn A15 nicht mit /CE verbunden ist dann ist der Cip ständig enabled und erlaubt dadurch ein "Roll over". Deshalb ist Addresse 32162 eigentlich 0, 32163 ist eigentlich 1, 32164 ist eigentlich 2, usw. Ich habe das nur mit einem 32k SRAM Chip getestet. Es funktioniert definitiv nicht mit einem 64k Chip und ich denke, es läuft ohne Änderung der Schaltung mit jedem Chip unter 32k.
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-Programming problems
+Programmier Probleme
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-- When you have unreliable results, use a shielded LPT cable
+- Wenn Sie unerwartete Ergebnisse erhalten dann benutzen Sie ein abgeschirmtes LPT-Kabel
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+- Die AVR Mikrocontroller enthalten einen Fehler wenn das Löschen nicht komplett ist. Es scheint sich an einer bestimmten Stelle aufzuhängen. Manchmal zeigt der Blank Check Report 'not empty' obwohl der Systemreport komplette Löschung angezeigt hat. Gemäß Atmel muss man VCC um 0,5 Volt (eine 1N4148 Diode in Serie) senken wenn das Löschen nicht funktioniert. (Solche Chips sind unzuverlässig und können deswegen nur benutzt werden wenn man sich sicher ist.) Das kann passieren wenn der Chip sehr häufig programmiert worden ist
-- The AVR chips have a bug, if the erase is not complete. It tend's to hang at some point. Sometimes although the system reports erased but blank check report "not empty". As per Atmel Data Errata You must drop the vcc by 0.5V ( a diode 1N4148 in Series ) if the erase is not happening. ( Such Chip's are unreliable and hence can be used only if you are sure ). This can happen after you have programmed the chip many times.
 <br/><br/>{{Languages}}
 [[Category:BASCOM Language Fundamentals/de]]