R5F212L4SNFP clock settings register

R5F212L4SNFP clock settings register

1. I have written code for using on chip high speed oscillator for R5F212L4SNFP MCU for maximum 20Mhz speed.
Is below settings & sequence ok?

2. How many nop to be added to get clock stable. currently I have added 4.



<code>

void set_system_clock(void)
{
/* Interrupt disable */
asm("FCLR I");

/* Protect off */
prc0 = 1;

/* cpu settings */
cm02 = 0; /* Peripheral function clock does not stop in wait mode */
cm05 = 1; /* XIN clock stops */
cm06 = 0; /* CM16, CM17 enabled */

cm10 = 0; /* Clock operates */
cm11 = 1; /* On-chip feedback resistor disabled */
cm13 = 0; /* Input ports P4_6, P4_7 */
cm14 = 0; /* Low -speed on-chip oscillator on */
cm15 = 1; /* XIN-XOUT drive capacity high */
cm16 = 0; /* System clock division select bits; no division */
cm17 = 0; /* System clock division select bits; no division */

ocd0 = 0; /* Oscillation stop detection function disabled */
ocd1 = 0; /* Oscillation stop detection interrupt disable */
ocd2 = 1; /* Selects on-chip oscillator clock */
ocd3 = 1; /* XIN clock stops */

fra00 = 1; /* High-speed on-chip oscillator on */
fra01 = 1; /* Selects high-speed on-chip oscillator */

fra20 = 0; /* High-speed on-chip oscillator frequency sw itching bits, Divide-by-2 mode */
fra21 = 0; /* High-speed on-chip oscillator frequency sw itching bits, Divide-by-2 mode */
fra22 = 0; /* High-speed on-chip oscillator frequency sw itching bits, Divide-by-2 mode */

/* let clock get stable */
asm ( "nop" );
asm ( "nop" );
asm ( "nop" );
asm ( "nop" );

/* Protect on */
prc0 = 0;

/* Interrupt enabled */
asm("FSET I");

} /* functin ends here */


</code>