help:so many warning,what means?

instance inst is missing source signal

Warning: Block or symbol div of instance inst overlaps another block or symbol
Warning: Port clk50m of type div and instance inst is missing source signal
Warning: Pin MCLK not connected
Warning: Verilog HDL expression warning at Led_flush.v(17): truncated operand with size 23 to match size of smaller operand (22)
Warning: No clock transition on div:inst|acc[11] register
Warning: Reduced register div:inst|acc[11] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[10] register
Warning: Reduced register div:inst|acc[10] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[9] register
Warning: Reduced register div:inst|acc[9] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[8] register
Warning: Reduced register div:inst|acc[8] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[7] register
Warning: Reduced register div:inst|acc[7] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[6] register
Warning: Reduced register div:inst|acc[6] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[5] register
Warning: Reduced register div:inst|acc[5] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[4] register
Warning: Reduced register div:inst|acc[4] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[3] register
Warning: Reduced register div:inst|acc[3] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[2] register
Warning: Reduced register div:inst|acc[2] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[1] register
Warning: Reduced register div:inst|acc[1] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[0] register
Warning: Reduced register div:inst|acc[0] with stuck clock port to stuck value GND
Warning: No clock transition on div:inst|acc[12] register
Warning: Reduced register div:inst|acc[12] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[20] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[20] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[19] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[19] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[18] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[18] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[17] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[17] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[16] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[16] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[15] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[15] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[14] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[14] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[13] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[13] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[12] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[12] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[11] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[11] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[10] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[10] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[9] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[9] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[8] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[8] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[7] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[7] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[6] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[6] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[5] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[5] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[4] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[4] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[3] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[3] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[2] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[2] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[1] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[1] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[0] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[0] with stuck clock port to stuck value GND
Warning: No clock transition on LED_flush:inst1|Mega_cnt[21] register
Warning: Reduced register LED_flush:inst1|Mega_cnt[21] with stuck clock port to stuck value GND
Warning: Output pins are stuck at VCC or GND
Warning: Pin LED1 stuck at GND
Warning: Pin LED2 stuck at GND
Warning: Pin LED3 stuck at GND
Warning: Pin LED4 stuck at GND
Warning: Design contains 2 input pin(s) that do not drive logic
Warning: No output dependent on input pin RST
Warning: No output dependent on input pin MCLK

pin stuck at gnd

You have not mensioned the tool or command that's generating these
warnings!! How can one help you!!
Its quite clear what these warning are for!!!! You clean ur RTL accordingly
to get zero warnings. Can you post the code so that I can get it clean an report it here!

out pins stuck at vcc or gnd

I presume u are getting these during synthesis .. from what i can a see u perhaps forgot to declare MCLK as clock . declare the clock and then come back with the source code may be then i can help