Intel C2550 FH8065401488912 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

Datasheet, Vol. 2 of 3

September 2014

336

Order Number: 330061-002US

Before programming new data into the GPBR buffer, the firmware sets both 

GPBRCTRL.BUFRST (which resets the buffer contents to 0) and GPBRCTRL.PTRRST 

(which resets the buffer pointer position). After the hardware has completed the reset, 

it clears both bits.

To enable the firmware to readback (verify) the contents of the GPBR buffer, the 

firmware sets only GPBRCTRL.PTRRST, which resets the buffer pointer position but 

leave the buffer contents intact. Consecutive reads then return the previously written 

buffer data.

The hardware provides read data payload starting from bits [7:0] of Dword0 of the 

buffer, then bits [15:8] of Dword0, and so on. All bytes must be programmed in the 

sequence to be sent out without gaps. The hardware counts the number of bytes 

indicated in the GPBRCTRL.BC register and start sending them out sequentially starting 

at byte 0 of Dword 0 until the byte count is decremented to 0.