8168EVM 烧写uboot到nand，no device available

最近弃用EZSDK，改用DVRRDK，用之前的EZSDK的SD卡启动之后中断准备烧写uboot来着，按照install guide里的步骤来的
ti8168_EVM#mw.b 0x81000000 0xFF
TI8168_EVM#tftp 0x81000000 uboot_NAND_DM816X_TI_EVM
Using DaVinci EMAC device
TFTP from server 192.168.0.11; our IP address is 192.168.0.6
Filename 'uboot_NAND_DM816X_TI_EVM'.
Load address: 0x81000000
Loading: #########################################
done
Bytes transferred = 208172 (32d2c hex)
TI8168_EVM#nandecc hw 2
HW ECC BCH8 Selected
TI8168_EVM#nand erase 0x0 0x260000

no devices available
TI8168_EVM#nand write.i 0x81000000 0x0 0x260000

no devices available
感觉uboot_NAND_DM816X_TI_EVM已经烧写完毕，进行nand erase时，出现no devices available，而且我检查启动信息时，有
NAND device: Manufacturer ID: 0x2c, Chip ID: 0xca (Micron NAND 256MiB 3,3V 16-bit)
NAND bus width 8 instead 16 bit
No NAND device found!!!
0 MiB，好像是没检测到nand，
后来我改了BTM，改成nand启动后，minicom没检测到boot信息，应该是没有烧写成功，有谁出现过这种情况吗？