RAM Test

Overview:

Block_Fill.zip contains the following EEPROM files to test your SRAM:

 - Block_Fill.asm

 - Block_Fill.hex

 - Block_Fill.lst

 - Block_Fill.obj or Block_Fill.bin

You can use the .hex file if you have an EEPROM programmer that accepts Intel hex files.

You can use the .obj  or .bin file (raw hex) if you have the Nano EEPROM Programmer by using the z80_eeprom_programmer file.

Note: many editors, except Sublime, will have trouble reading the Hexadecimal file containing the raw machine code unless there is a Hexadecimal setting for the editor. See this link to install a free hex editor named XVI32.

The .asm file is the documented assembly language file. Note that the code contained therein is a variation on the traditional use of the LDIR command shown in the program below:

  LD HL, 0000h    ; Pointer to the source.

  LD DE, 8000h    ; Pointer to the destination.

  LD BC, 8000h    ; Number of bytes to move.

  LDIR                    ; Copies BC bytes from (HL) to (DE).

                              ; BC is decremented as each byte from HL location is copied to DE location, and then HL and DE are incremented.

The .LST file within the Block_Fill.zip file is the most useful of all the files because it contains addresses, machine code, assembly code and your comments.

Video: Z80 system executing the Block_Fill RAM test

Clicking on the thumbnail gif above will provide an HD video (49.6MB, .mp4 format)

Follow the Code:

In this video we follow every line of code in our 13-byte Block_Fill.asm program as it executes.

You will see M1/MR/RD flash during the start of each instruction Fetch, and MR/RD as each additional data byte is fetched in multi-byte instructions like "LD HL, 8000h" (0x21 0x00 0x80).

You will also see M1/MR/WR flash as the data pattern FF is written into the first RAM location, address 0x8000 (32,768).

As with most videos watched in your web browser, you can pause/resume the playback using your <SpaceBar>.

Z80 Assembly Language Programming

Visit Z80 Programming IV to learn how the Assembly code works for this circuit.

Video: Line by line examination of the Block_Fill RAM test

Clicking on the thumbnail gif above will provide an HD video (43.5MB, .mp4 format)