MIOS8 by default updates the SRIO chain @ 1kHz.
8 enable lines => 1kHz/8 = 125 Hz.
I found this in the forum:
At 1 MHz, the CPU can execute up to 10 instructions (note that a branch/goto will cost 2 cycles!) - this should be sufficient, considered that the driver is written in assembly.
Future compatibility with MBHP_CORE_STM32:
I've proven, that this clock synchronisation method also works with STM32F103, see sid.c driver.
At 72 MHz, there are enough cycles free so that assembly language isn't really required. Even 4 MHz should be achievable.
Alternatively, we could use one of two available SPI ports of the MBHP_CORE_STM32 module (J9 or J16) for full background control w/o bitbanging. This would restrict some usecases (e.g. DOUT SRIO or I2S normaly connected to J9, SD Card normaly connected to J16), but would unload the CPU almost completely, so that LCD transfers can be handled from a background task w/o disabling interrupts. As most application won't require a SD Card, J16 is really predestinated for such jobs.
I hope that this information wasn't too confusing...
When i calculate now.I see a rate more about 125kHz at 8 enable lines with the STM32 (4MHz).
I need details.
In the Datasheet i´ve read Correspond to high speed MPU bus interface
- 2 MHz (when VCC = 5V)
-External clock frequency (fcp) min.125kHz typ.250kHz max.350kHz
-Clock oscillation frequency (fOSC) min.190kHz typ.270kHz max.350kHz
andRelationship between Oscillation Frequency and Liquid Crystal Display Frame
The liquid crystal display frame frequencies of Figure 22 apply only when the oscillation frequency is 270
kHz (one clock pulse of 3.7 ms).
1/8 duty cycle
1 frame = 3.7 μs * 400 (clocks) * 8 = 11850 μs = 11.9 ms
Frame Frequency = 1/11,9ms = 84,3HzI DON´T REALLY UNDERSTAND, WHAT THE PROBLEM IS..?!
The Displays show only defined Values and Setups. They don´t display any Animated Graphics.
Only 1 of the 8 or 16 CLCDs shows the actual TrackTime.
When my C Programming scills are so good, i will let one of them act like a Anaylzer Display.
Must be the Update frequence so high to drive them with the Enable line over a DOUT PIN?
I´m confused !!
Edited by CSC, 19 August 2011 - 04:59.