projects / sigrok-firmware-fx2lafw.git / blame
| Commit | Line | Data |
|---|---|---|
| 3608c106 UH |
1 | Notes on Various things I've learned about SDCC and the FX2 |
| 2 | ||
| 3 | * libusb on Linux | |
| 4 | * cycfx2prog: http://www.triplespark.net/elec/periph/USB-FX2/software/index.html | |
| 5 | - most of this functionality is now in the fx2load package for python | |
| 6 | - which is in examples/fx2 | |
| 7 | * sdcc has sdcc/support/scripts/keil2sdcc.pl which I used to create the fx2regs.h file from the keil header. | |
| 8 | * sdcc is little endian, keil is big endian (important if doing usb communication) | |
| 9 | * xdata can go up to 64k on the EZ-USB development board but | |
| 10 | - the fx2 chip itself only has 16k (end at 0x4000) Firmware written for other than the dev board | |
| 11 | - should use --xram-size --xram-loc etc to make sure it isn't using memory beyond 16k. | |
| 12 | * linux has objcopy, which can be used in place of Hex2bix for bix files | |
| 13 | - objcopy -I ihex -O binary --pad-to=8192 input [output] | |
| 14 | ||
| 15 | ||
| 16 | Memory | |
| 17 | * 256 bytes internal | |
| 18 | - lower 128=registers/bits (direct or indirect) | |
| 19 | - upper 128=stack (or whatever but only indirect addressing) | |
| 20 | - sfs occupy upper 128 space only direct addressing | |
| 21 | ||
| 22 | * external | |
| 23 | - 16k on chip 0-0x3fff | |
| 24 | - 512 bytes on chip scratch ram 0xe000 - 0xe1ff (data memory only) | |
| 25 | - epbuffers and control at 0xe200-0xffff (data memory only) | |
| 26 | ||
| 27 | Only the on chip 16k and 512 bytes can be uploaded w/ eeprom or downloaded to host with SETUPPTR | |
| 28 | Might be possible to load the descriptors to the scratch ram instead of code ram area? | |
| 29 | ||
| 30 | sdcc data types | |
| 31 | data/near=direct addressable internal memory (default for model-small) | |
| 32 | xdata/far=external ram (default for model-large) | |
| 33 | idata=indirect addressable internal memory | |
| 34 | pdata=access to xdata area, but uses sfr to get to address (sdcc 4.1) | |
| 35 | code=code memory, study this more. | |
| 36 | bit=uses lower 128 bit area | |
| 37 | ||
| 38 | ||
| 39 | TODO: | |
| 40 | * Possibly add CKCON and bmSTRETCH customization | |
| 41 | * IN2CLR and INT4CLR registers can be used intead of explicitly clearing int2 and int4 interrupts. (Faster) | |
| 42 | See (15.5) |