[BUG] "gave incorrect register advice for STM32WLE4, couldn't read local PDF"

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude is occasionally confidently wrong and cites references that are incorrect. Claude gave advice on how to use some registers on an STM32 MCU. These registers do not exist on said micro under the same name, nor did the functionality Calude was suggesting I use, exist in the different registers. Claude said do this :-

// Wait for alarm registers to become writable (RM 30.3.9)
while (!(RTC->ICSR & RTC_ICSR_ALRAWF));

But these dont exist on STM32LWE4C8Uxx MCU. Claude cites a section of the Reference Manual to back up its advice. Opening reference manual for STM32LWE4C8Uxx I could not find the source of Claudes information. Interestingly CoPilot gives exactly the same incorrect advice referring a prior hardware peripheral revision and different model of MCU -- are they both getting there information from the same source...but what source!!!!????

What Should Happen?

Claude should check all it's citation sources as otherwise its giving , worst case, plain wrong advice.
To make things worse, you have to haggle with Claude to make it say....oh..ok..acutally you're right. Claude sound far too confident. Be confident sure, but after youve checked your sources!

Claude Model

Claude Sonnet 4.6.

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal