请问c6748必须要接ddr吗？

请问c6748必须要接ddr吗，我直接做了一款板子，没有接ddr，jtag testing通过，但是挂载gel文件时出现：
C674X_0: Output: Target Connected.
C674X_0: Output: ---------------------------------------------
C674X_0: Output: Memory Map Cleared.
C674X_0: Output: ---------------------------------------------
C674X_0: Output: Memory Map Setup Complete.
C674X_0: Output: ---------------------------------------------
C674X_0: Output: PSC Enable Complete.
C674X_0: Output: ---------------------------------------------
C674X_0: Output: PLL0 init done for Core:456MHz, EMIFA:114MHz
C674X_0: Output: DDR initialization is in progress....
C674X_0: Trouble Reading Memory Block at 0x1c14188 on Page 0 of Length 0x4: (Error -1060 @ 0x1C14188) Device is not responding to the request. Reset the device, and retry the operation. If error persists, confirm configuration, power-cycle the board, and/or try more reliable JTAG settings (e.g. lower TCLK). (Emulation package 5.1.232.0)
C674X_0: GEL: Error while executing OnTargetConnect(): Target failed to read 0x01C14188 at (*((unsigned int *) (0x01C14000+0x188))&=~(0x00000020)) [Tronlong_C6748.gel:237] at device_PLL1(12, 0, 0, 1, 2) [Tronlong_C6748.gel:431] at Set_DDRPLL_156MHz() [Tronlong_C6748.gel:437] at Set_DDR2_156MHz() [Tronlong_C6748.gel:444] at Core_456MHz_DDR2_156MHz() [Tronlong_C6748.gel:261] at CPU_PLL_PSC_DDR_Init() [Tronlong_C6748.gel:251] at OnTargetConnect() .
C674X_0: Trouble Reading Register CSR: (Error -1060 @ 0x41) Device is not responding to the request. Reset the device, and retry the operation. If error persists, confirm configuration, power-cycle the board, and/or try more reliable JTAG settings (e.g. lower TCLK). (Emulation package 5.1.232.0)
C674X_0: Trouble Reading Register CSR: (Error -1060 @ 0x41) Device is not responding to the request. Reset the device, and retry the operation. If error persists, confirm configuration, power-cycle the board, and/or try more reliable JTAG settings (e.g. lower TCLK). (Emulation package 5.1.232.0)
好像是配置到ddr的时钟时出错了，请问是需要修改gel文件吗？还是必须要接一块ddr？