Documentation for “Zerocat Chipflasher” as of Tue, 11 Feb 2025 14:22:39 +0100
Repository:
Version: v2.1.1-0-7ab6f93df
Branch: master

../../firmware2/src/kick2.spin.nointerface.html

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Zerocat Chipflasher --- Flash free firmware, kick the Management Engine.

File kick2.spin --- The top object file for this firmware2 project.

This file is part of Zerocat Chipflasher.

See end of file for terms of use.

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IMPORTANT NOTICE
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* On PCBv1 aka board-v1, the SPI CE# line is pulled up via trimmer.

Adjust a reasonable value, not too small.

* On PCBv2.0 aka board-v2.0, the SPI CE# line is pulled up via R23 and R10.

These resistors are populated with 91 Ohm each, forming a pull-up
value of 45.5 Ohm on the first series of devices, shipped in 2024 and
earlier.

That is too small!

(On the chip flasher development board, this pull-up is set to
47.62 Ohm, which works in test setups with hand-made wiring.)

As a workaround, cut one end of R10 with a pince and twist the
resistor aside, carefully. The remaining pull-up value is 91 Ohm
(the value of R23), which should be a reasonable value for most use
cases.

In 2025, the PCB will provide sockets for R23 and R10, such that
this pull-up can be adjusted. However, the formed resistor value
must not be smaller than 42 Ohm, otherwise the Propeller pins 0 and
1 will be damaged.

These equations apply:

1 1 1
R_pull = --- , x = ----- + -----
x R23 R10

* On PCBv2.1 aka board-v2.1, the SPI CE# line is pulled up via trimmer,
which is digitally monitored.

In 2025, the PCBv2.1 candidate for FSF Respect Your Freedom (RYF)
certification uses R23 and R10 as an offset for the trimmer, to
protect Propeller pins even if the trimmer would be adjusted to zero.

These equations apply:

1
R_pull = R_trim + --- ,
x

R_trim = 0..500 (approx.) ,

1 1
x = ----- + -----
R23 R10

The value of R_pull is displayed in the menu of the `connect`
utility. Upon change, the display should be refreshed by user's key
input.

A value of 91 Ohm is still considered as a reasonable value for
many use cases, however, some targets require an adjustment.

# Object Configuration (set via Makefile)

Tell us which interface to use:

* connect
* flashrom
* terminal
* none

# Interface Description

Object "../../firmware2/src/kick2" Interface:

PUB kick2

Program: 231 Longs
Variable: 12 Longs

# Loaded Objects

Load pin configuration object.
Load ASCII object.
Load error object.

# Constants

* System Speed
* Basic Timing
* Project's Memory Usage

# Functions

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PUB kick2

This is the Chipflasher's new firmware, coded in Spin/PASM.

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Terms of Use:

Zerocat Chipflasher is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

Zerocat Chipflasher is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License along
with Zerocat Chipflasher. If not, see <http://www.gnu.org/licenses/>.

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