Hi
Should be easy to test outputs:
1: Just don't forget to configure as output (eg.):
#define PTG0 0x01
#define LED_1 PTG0
PTG |= (LED_1); // prepare output high
DDRG |= (DEMO_LED_1); // set output port bits
PTG ^= (DEMO_LED_1); // flip output to '0'
PTG ^= (DEMO_LED_1); // flip output back to '1'
2. The NE64 is a 3V3 device and so the output changes from 3V3 to 0V. If you need 5V then you will have to use a level converter.
Cheers
Mark Butcher
www.mjbc.ch
Hi
Sorry, I thought the question was general and I missed the A+B port detail.
The EVB board has some mode jumpers and which are read on startup and configure whether port A + B are expanded bus pins or ports. I think that if you set MODA, MODB, MODC all to zero you will have real single chip mode where all ports are general purpose ports - you may have to watch with external memory devices, I have never worked with the EVB so check the manual.
Cherrs
Mark Butcher
about level converter you told me about , is it a device I can buy it directly or a circuit and I have to assemble it ??
is there any other way instate of level converters?
thanks
Ah.Kh.
It depends on what you want to drive.
If it is a logic output requiring 5V/0V then you can use a buffer - 74HCxx - I don't know exactly which family is best suited without checking the data sheets. Just make sure that the buffer can be powered with 5V and understands the worst case logic levels supplied by the NE64 outputs (for example if the buffer required 0,7V VCC minimum to see a logic '1' then it will not work but if it needs 2,7V then it is fine).
If you are driving a load then a simple transistor/MOSFET will also be fine since it allows high voltages to be switched form a 3V3 logic output.
If you need bidirectional lines then there are some special devices with 3V3 and 5V supplies which do all conversions - can't remember their names but a search will surely find them.
If you need to read inputs of 5V logic level then a simple resistive divider will mostly be fine - eg. 18k / 33k (although the signal speed will restrict the highest resistance values which can be used). There are also some special devices, such as the 74HC4049 for converting high voltage CMOS inputs to lower logic levels.
Cheers
Mark Butcher