---
title: "W7100A boot problem"
url: "https://maker.wiznet.io/forum/9706"
markdown_url: "https://maker.wiznet.io/forum/9706/md"
type: "Forum topic"
category: "MCU & Boards"
author: "setime"
created: "2013-11-27T14:04:59+09:00"
last_activity: "2017-05-04T08:30:34+09:00"
language: "en"
views: 907
replies: 3
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W7100A boot problem

## Question

Asked by setime on 2013-11-27 in MCU & Boards.

Hi, WizNet.

I use WizIsp to program W7100A and mistakenly tried to program ~64KB of code into 255B data memory. Loading stopped at 17% of progress. Now WizISP can’t establish a connection with W7100A.
I broke a bootloader code? Can I run the chip again?

Regards, setime.

## Replies

### Reply 1 by hjjeon0608, 2013-11-29

Hi, setime.

Bootloader doesn’t matter with code flash and data memory.

So, that W7100A works fine is correct. So I think there are other problems.

I want to know you use EVB or your own board and if you have another W7100, test same procedure and confirm ISP works fine.

Best regards.

### Reply 2 by setime, 2013-11-29

Hi, hjjeon0608. Thank for reply.

Sorry, I didn’t mention that W7100A is mounted on the WIZ107SR module, i use it to implement own application.
Now I am working with another WIZ107SR module and its successful programming as before. But a broken module at the same time does not respond to attempts to establish a connection via COM port.

Regards, setime

### Reply 3 by hjjeon0608, 2013-12-02

Hi, setime.

I tested 107SR with your procedure.

But I don’t have seen problem like yours.

So, I recommend to request RMA.

Best regards.

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Source: https://maker.wiznet.io/forum/9706