600 Series Chipset Family Platform Controller Hub

Datasheet, Volume 1 of 2

ID 648364
Date 05/10/2022
Document Table of Contents

16550 8-bit Addressing - Debug Driver Compatibility

Note:The PCH UART host controller is not compatible with legacy UART 16550 debug-port drivers. The UART host controller operates in 32-bit addressing mode only. UART 16550 legacy drivers only operate with 8-bit addressing. In order to provide compatibility with standard in-box legacy UART drivers a 16550 Legacy Driver mode has been implemented in the UART controller that will convert 8-bit addressed accesses from the 16550 legacy driver to the 32-bit addressing that the UART host controller supports.The UART 16550 8-bit Legacy mode only operates with PIO transactions. DMA transactions are not supported in this mode.