忘備録-備忘録

技術的な備忘録

RX210のクロックをPLLに切り替えるプログラム

2015-03-26 07:17:08 | RX210
RX210のクロックをPLLに切り替えるプログラムです。ルネサスエレクトロニクスのサンプルコードを単純化したものです。水晶振動子の発振周波数が20MHzの時にCPUの動作クロックが50MHzとなり周辺機器のクロックが25MHzとなります。

  1. /* RX210 cpuのクロックをPLLに切り替えるプログラム */
  2. /* 水晶振動子の発振周波数が20MHzの時にCPUの動作クロックが50MHzとなり周辺機器のクロックが25MHzとなる。 */
  3.                                                                           
  4. #include "iodefine.h"
  5. #include <machine.h>
  7. void change_oscillation_PLL(void)
  8. {
  9.     unsigned int i;
  11.     /* ---- Enable write protection ---- */
  12.     /* PRCR - Protect Register
  13.     b15:b8 PRKEY - PRC Key Code - A5h
  14.                   (The write value should be A5h to permission writing PRCi bit)
  15.     b7:b4 Reserved - The write value should be 0.
  16.     b3 PRC3 - Protect Bit 3 - Write disabled
  17.     b2 PRC2 - Protect Bit 2 - Write enabled
  18.     b1 PRC1 - Protect Bit 1 - Write enabled
  19.     b0 PRC0 - Protect Bit 0 - Write enabled */
  20.     SYSTEM.PRCR.WORD = 0xA507;
  22.     /* ---- Set the VRCR register ---- */
  23.     SYSTEM.VRCR = 0x00;
  25.     /* ---- Set the main clock oscillator drive capability ---- */
  26.     /* MOFCR - Main Clock Oscillator Forced Oscillation Control Register
  27.     b7 Reserved - The write value should be 0.
  28.     b6 MOSEL - Main Clock Oscillator Switch - Resonator
  29.     b5:b4 MODRV2 - Main Clock Oscillator Drive Capability Switch 2
  30.                       - 16 MHz to 20 MHz
  31.     b3:b1 MODRV - Main Clock Oscillator Drive Capability Switch
  32.                       - 16 MHz to 20 MHz non-lead type ceramic resonator
  33.     b0 Reserved - The write value should be 0. */
  34.     SYSTEM.MOFCR.BYTE = (0x30);    /* Drive capability : 20 MHz crystal resonator */
  36.     /* ---- Set wait time until the main clock oscillator stabilizes ---- */
  37.     /* MOSCWTCR - Main Clock Oscillator Wait Control Register
  38.     b7:b5 Reserved - The write value should be 0.
  39.     b4:b0 MSTS - Main Clock Oscillator Waiting Time
  40.                       - Wait time is 131072 cycles (approx. 6.55 ms). */
  41.     SYSTEM.MOSCWTCR.BYTE = (0x0D);    /* Wait control register : 131072 cycles (approx. 6.55 ms) */
  43.     /* ---- Operate the main clock oscillator ---- */
  44.     /* MOSCCR - Main Clock Oscillator Control Register
  45.     b7:b1 Reserved - The write value should be 0.
  46.     b0 MOSTP - Main Clock Oscillator Stop - Main clock oscillator is operating. */
  47.     SYSTEM.MOSCCR.BYTE = 0x00;
  49.     while (0x00 != SYSTEM.MOSCCR.BYTE)
  50.     {
  51.         /* Confirm that the written value can be read correctly. */
  52.     }
  55.     /* ---- Wait processing for the clock oscillation stabilization ---- */
  56.     for(i=0;i<100;i++) nop();</li>
  58.     /* ---- Set the PLL division ratio and multiplication factor ---- */
  59.     /* PLLCR - PLL Control Register
  60.     b15:b13 Reserved - The write value should be 0.
  61.     b12:b8 STC - Frequency Multiplication Factor Select
  62.                       - Frequency multiplication factor is multiply-by-10.
  63.     b7:b2 Reserved - The write value should be 0.
  64.     b1:b0 PLIDIV - PLL Input Frequency Division Ratio Select
  65.                       - PLL input division ratio is divide-by-2. */
  66.     SYSTEM.PLLCR.WORD = (0x0901);    /* Division ratio and multiplication factor : divide-by-2, multiply-by-10 */
  68.     /* ---- Set wait time until the PLL clock oscillator stabilizes ---- */
  69.     /* PLLWTCR - PLL Wait Control Register
  70.     b7:b5 Reserved - The write value should be 0.
  71.     b4:b0 PSTS - PLL Waiting Time
  72.                       - Wait time is 65536 cycles (approx. 655.36 us). */
  73.     SYSTEM.PLLWTCR.BYTE = (0x09);    /* Wait control register : 65536 cycles (approx. 655.36 us) */
  75.     /* ---- Operate the PLL clock oscillator ---- */
  76.     /* PLLCR2 - PLL Control Register 2
  77.     b7:b1 Reserved - The write value should be 0.
  78.     b0 PLLEN - PLL Stop Control - PLL is operating. */
  79.     SYSTEM.PLLCR2.BYTE = 0x00;
  81.     /* ---- Wait processing for the clock oscillation stabilization ---- */
  82.     for(i=0;i<100;i++) nop();</li>
  84.     /* ---- Set the operating power control mode ---- */
  85.     /* OPCCR - Operating Power Control Register
  86.     b7:b5 Reserved - The write value should be 0.
  87.     b4 OPCMTSF - Operating Power Control Mode Transition Status Flag
  88.     b3 Reserved - The write value should be 0.
  89.     b2:b0 OPCM - Operating Power Control Mode Select - High-speed operating mode */
  90.     SYSTEM.OPCCR.BYTE = (0x00); /* High-speed operating mode */
  92.     while (0 != SYSTEM.OPCCR.BIT.OPCMTSF)
  93.     {
  94.         /* Confirm that the operation power control mode transition completed. */
  95.     }
  97.     /* ---- Set the internal clock division ratio ---- */
  98.     /* SCKCR - System Clock Control Register
  99.     b31:b28 FCK - FlashIF Clock(FCLK) Select - divide-by-4
  100.     b27:b24 ICK - System Clock (ICLK) Select - divide-by-2
  101.     b23 PSTOP1 - BCLK Pin Output Control - disabled. (Fixed high)
  102.     b22:b20 Reserved - The write value should be 0.
  103.     b19:b16 BCK - External Bus Clock (BCLK) Select - divide-by-4
  104.     b15:b12 Reserved - The write value should be 0001b.
  105.     b10:b8 PCLKB - Peripheral Module Clock B(PCLKB) Select - divide-by-4
  106.     b7:b4 Reserved - The write value should be 0001b.
  107.     b3:b0 PCLKD - Peripheral Module Clock D(PCLKD) Select - divide-by-2 */
  108.     SYSTEM.SCKCR.LONG = 0x21821211;    /* ICLK,PCLKD: divide-by-2 PCLKB,BCLK,FCLK: divide-by-4 */
  110.     while (0x21821211 != SYSTEM.SCKCR.LONG)
  111.     {
  112.          /* Confirm that the written value can be read correctly. */
  113.     }
  115.     /* ---- Set the BCLK pin output ---- */
  116.     /* BCKCR - External Bus Clock Control Register
  117.     b7:b1 Reserved - The write value should be 0.
  118.     b0 BCLKDIV - BCLK Pin Output Select - divide-by-2 */
  119.     SYSTEM.BCKCR.BYTE = 0x01;
  121.     while (0x01 != SYSTEM.BCKCR.BYTE)
  122.     {
  123.         /* Confirm that the written value can be read correctly. */
  124.     }
  126.     /* ---- Set the internal clock source ---- */
  127.     /* SCKCR3 - System Clock Control Register 3
  128.     b15:b11 Reserved - The write value should be 0.
  129.     b10:b8 CKSEL - Clock Source Select - PLL circuit is selected.
  130.     b7:b1 Reserved - The write value should be 0. */
  131.     SYSTEM.SCKCR3.WORD = (0x0400);    /* PLL */
  133.     while ((0x0400) != SYSTEM.SCKCR3.WORD)
  134.     {
  135.         /* Confirm that the written value can be read correctly. */
  136.     }
  138.     /* ---- Disable write protection ---- */
  139.     /* PRCR - Protect Register
  140.     b15:b8 PRKEY - PRC Key Code - A5h
  141.                   (The write value should be A5h to permission writing PRCi bit)
  142.     b2 PRC2 - Protect Bit 2 - Write disabled
  143.     b1 PRC1 - Protect Bit 1 - Write disabled
  144.     b0 PRC0 - Protect Bit 0 - Write disabled */
  145.     SYSTEM.PRCR.WORD = 0xA500;
  147. }
  150. void main(void)
  151. {
  152.     unsigned int i;
  154.     change_oscillation_PLL();            //クロックソースPLL
  156.     PORTC.PDR.BYTE = 0xFF;
  157.     PORTC.PODR.BYTE = 0x00;
  158.     PORTA.PDR.BYTE = 0xFF;
  159.     PORTA.PODR.BYTE =0x00;
  160.     PORTB.PDR.BYTE = 0xFF;
  161.     PORTB.PODR.BYTE = 0xFF;
  163.     while(1) {
  164.         PORTC.PODR.BYTE = ~PORTC.PODR.BYTE;
  165.         PORTA.PODR.BYTE = ~PORTA.PODR.BYTE;
  166.         PORTB.PODR.BYTE = ~PORTB.PODR.BYTE;
  167.         for(i=0;i<500000;i++) nop();</li>
  168.     }
  170. }


最新の画像［もっと見る］

コメントを投稿