Hello @cszhang ,
Software user manual as well as other available documentation can be downloaded from the SJA1110 main page - https://www.nxp.com/products/SJA1110 - from Documentation section, under Secure files.

Requested documentation for this product is under control release, accessible under NDA (Non-Disclosure Agreement) via Secure Files.
Please Request Access here: https://www.nxp.com/webapp-signup/docstoreReg
Please note, during the form submission you will be asked to upload valid NDA copy. If your company does not have any yet please fill the form for NDA first:
https://www.nxp.com/webapp-signup/ndaReqForm
When NDA is ready you can request secure files access
Kindly check FAQs to understand the process:
https://www.nxp.com/support/support/secure-access-rights:SEC-ACCESS
https://www.nxp.com/support/support/secure-access-rights/secure-access-rights-faqs:SEC-ACCESS-FAQS
Please note that Automotive Ethernet is subject to export control policies and additional approvals may be required even after NDA and Secure Files access is granted.
As it has been discussed in this thread Where to download SJA1110 RTM 1.0.2 , SJA110 SDK is no longer available for new customers and that software development continues in the Real-Time Drivers (RTD) ecosystem.
Best regards,
Pavel