Commit Graph

9 Commits

Author SHA1 Message Date
Gregory Nutt
ef604f8d43 z20x: Performance Improvements
- boards/z80/ez80/z20x/scripts/z20x_*.linkcmd:  Reduce from 4 to 1 wait state.  That i sufficient because of the slow clocking of the eZ80F92
  - boards/z80/ez80/z20x/src/w25_main.c:  Replace CRC algorithm with simple, less time consuming check sum.
  - boards/z80/ez80/z20x/configs/nsh:  Rename the nsh_ram configuration to just nsh
  - boards/z80/ez80/z80x/configs/hello: Add simpler program to make debugging the loader easier.
2020-03-14 00:05:38 +01:00
Gregory Nutt
bfc15a6295 z20x: Fixes related to W25 boot configurations.
arch/z80/src/ez80/ez80_timerisr.c:  Correct a mismatch between the programmed reload value and the timer input clock frequency.

arch/z80/src/ez80/ez80f92.h:  Correct error in timer input clock divider:  Bits 2-3, not bits 3-4.

boards/z80/ez80/z20x/src/w25_main.c:  Correct an uninitialized return value; private function was not declard static.
2020-03-11 18:24:43 -03:00
Gregory Nutt
199b4d6852 z20x: Changes to reduce serial Rx data overrun
boards/z80/ez80/z20x:  Increase RX buffer size to 4Kb, reduce BAUD to 2400 in w25boot configuration
arch/z80/src/ez80/ez80_serial.c:  Reduce Rx FIFO trigger level for eZ80F92 to 1 so that will respond more quickly to incoming data.
2020-03-09 22:51:54 +01:00
Gregory Nutt
029680fb50 boards/z80/ez80/z20x: Remove the nsh_flash configuration.
The nsh_flash configuration is too big and will never fit into the eZ80F92's small internal FLASH.
2020-03-01 14:50:37 +01:00
Gregory Nutt
41ef33bded eZ80: Fix optimization issues
board/z80/ez80/*/scripts/Make.defs:  Fix optimization definition use in assembly flags.  It was using the compiler optimization settings instead of the assembler optimization settings.  Hence, enabling optimization would could cause assembler command line errors.

arch/z80/src/ez80/Toolchain.defs:  Back out some work arounds.  Now compiler optimization flags can again set set without assembler command line errors.

boards/z80/ez80/z20x/README.txt:  Trivial update to size/optimization discussion.
2020-02-29 12:43:28 -03:00
Gregory Nutt
e309128313 boards/z80/ez80/z20x/README.txt: Update README. 2020-02-29 09:24:23 +01:00
Gregory Nutt
8c00e43c1a arch/z80/src/ez80: Fix eZ80F92 Interrupt Controller
The eZ80F92 interrupt controller is very different from the eZ80F91.  The eZ80F91 has:

1. Four byte interrupt vectors
2. The vector base address register is 16-bit so the vector table can lie in RAM

Whereas the eZ80F92 has:

1. Two byte interrupt vectors
2. An 8-bit vector base address

This means that the vectors must lie in the first 16-bits of FLASH and there must be a "trampoline" to get to interrupt handlers outside of the first 64-Kb of FLASH.
2020-02-28 19:45:28 +00:00
Gregory Nutt
161104c76a eZ80/z20x: Correct uninitialized stack memory
arch/z80/src/ez80/Toolchain.defs:  Correct some CFLAGS when optimization suppressed.

arch/z80/src/ez80/Kconfig arch/z80/src/ez80/ez80_emac.c:  Remove configuration option for selecting EMAC RAM address.  This is duplicated and possibly conflicting.  The correct address for the RAM is provided in the linker command file.  The RAM should be configured once and using this single definitions.

arch/z80/src/ez80/ez80_startup.asm and arch/z80/src/ez80/ez80f9*_init.asm.  Move RAM and FLAH intialization out of MCU-specific logic to common start-up logic.  We cannot call any functions until SRAM is initialized and the stack is properly initialized because the return address is stored on the stack.  Use internal SRAM for the IDLE stack to avoid the chicken'n'egg problem.

boards/z80/ez80/z20x/configs/sdboot/sdboot.zdsproj:  Discuss build environments.
2020-02-27 22:53:27 +01:00
Gregory Nutt
5a3e8874bc boards/z80/ez80/z20x: Initial port to z20x board.
The Z20X is a simple expandable DIY computing system, built around the eZ80 microprocessor.  Reference: https://z20x.computer
2020-02-21 15:20:36 +01:00