Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Freescale Semiconductor/MK61F15WS/DDR/CR15#0x0
PUREF=0
DDR Control Register 15
TXSNR parameter
Self Refresh
Reserved
Power Up Refresh
0 (0): Disabled
1 (1): Enabled
https://github.com/cmsis-svd/cmsis-svd-data