THS788 not locking

Hi,

This is my first attempt with the THS788.

I am providing a clean 200 MHz clock to the device (measured with 1G scope)

When i initialize the THS788, i notice that the two DLL does not lock. (i wait about 500ms at start up, after reset)

Here is the result of the start sequence (sent via a UART port)

Init THS788...
id = 8010
status = 1
ctrl = 0
wriring 2 to ctrl (0x80)
ctrl = 0
status = 1
wriring A000 to ctrl (0x80)
ctrl (0x80) = A000
ctrl (0x81) = 0
status = 1

So, i can read the ID correctly. I issue a software reset (by wriring to 2 to Ctrl register), then i write 0xA000 to enable RCLK and SYNC (i've seen that on another thread).

However, the problem is, the status always returns 1, shouldn't it return 0xD, or at least 0x9 ?

Why does the 1G2 DLL won't lock... is there any way to verify that?

I am using DS4M200 from Maxim to generate the 200MHz clock.. 

if this can help, here is the init sequence code:

ths_read_reg(0x83,(uint8_t*)&id);
    debug("id = ");
    put_n(id,16);
    debug("\n\r");

    ths_read_reg(0x82,(uint8_t*)&status);
    debug("status = ");
    put_n(status,16);
    debug("\n\r");

    ths_read_reg(0x80,(uint8_t*)&ctrl);
    debug("ctrl = ");
    put_n(ctrl,16);
    debug("\n\r");

    ctrl = (1<<1) ;
    debug ("wriring ");
    put_n(ctrl,16);
    debug (" to ctrl (0x80)\n\r");
    ths_write_reg(0x80,(uint8_t*)&ctrl);
    DelayMs(50);
    ths_read_reg(0x80,(uint8_t*)&ctrl);
    debug("ctrl = ");
    put_n(ctrl,16);
    debug("\n\r");

    DelayMs(250);

    ths_read_reg(0x82,(uint8_t*)&status);
    debug("status = ");
    put_n(status,16);
    debug("\n\r");


    ctrl = (1<<15) | (1 << 13);
    debug ("wriring ");
    put_n(ctrl,16);
    debug (" to ctrl (0x80)\n\r");
    ths_write_reg(0x80,(uint8_t*)&ctrl);

    ths_read_reg(0x80,(uint8_t*)&ctrl);
    debug("ctrl (0x80) = ");
    put_n(ctrl,16);
    debug("\n\r");

    ths_read_reg(0x81,(uint8_t*)&ctrl);
    debug("ctrl (0x81) = ");
    put_n(ctrl,16);
    debug("\n\r");

    DelayMs(250);

    ths_read_reg(0x82,(uint8_t*)&status);
    debug("status = ");
    put_n(status,16);
    debug("\n\r");

Any ideas?

Thanks a lot,