Can a task period larger than tick time (rtx51tny)?

The module just include at89s52,ps7219,ds12887a,leds.When use no os,have a delay sub as

void Soft_Delay_ms(unsigned char x)
{
    unsigned int i=0;
    i = x / Tma;
    while(x--) _nop_();
}

,and use Soft_Delay_us(50) can initial ps7219.
when take rtx51tny os,Soft_Delay_us(50) make tasks not to switch.so the sub be changed as

void Soft_Delay_ms(void)
{
    os_wait (K_TMO , 10 , 0);
/*
xtal: 24M
INT_CLOCK: 10000
TICK : 5ms
*/
}

,by this way ,tasks can switch, and the ps7219 never be initial well.what is the matter?
in the typical application,how to make program wait the
'slow equipment'?
best regards