Dallas Semiconductor has the DS5000/5001/5002 devices that have up to 64K of XDATA on-chip. These devices are RAM-based with battery backup. They can be reprogrammed using a serial interface or via parallel programmer.

Myson Technology has a CS6208 which has 32K on-chip XRAM.

Triscend TE520 has 40K on-chip XRAM.

Jon