ルネサス製のRX210マイコンのSCI0を使用したシリアル通信プログラムのサンプルです。
割込みは使用していません。
割込みは使用していません。
- #include "iodefine.h"
- #include <stdio.h>
- #include <machine.h>
- /*
- * SCI0初期化
- * 57600bps: 8bit: stop bit 1: Parity none
- * PCLK 25MHz
- */
- void SCI_Init (void)
- {
- /* ---- SCI interrupt request is disabled ---- */
- IR(SCI0,ERI0) = 0;
- IR(SCI0,RXI0) = 0;
- IR(SCI0,TXI0) = 0;
- IR(SCI0,TEI0) = 0;
- /* ---- Initialization of SCI ---- */
- /* PRCR - Protect Register
- b15:b8 PRKEY - PRC Key Code - A5h (The write value should be A5h to permission writing PRCi bit)
- b7:b4 Reserved - The write value should be 0.
- b1 PRC1 - Protect Bit 1 - Write enabled */
- SYSTEM.PRCR.WORD = 0xA502;
- /* The module stop state of SCIn is canceled */
- MSTP(SCI0) = 0;
- /* Enable write protection */
- SYSTEM.PRCR.WORD = 0xA500;
- /* SCR - Serial Control Register
- b7 TIE - Transmit Interrupt Enable - A TXI interrupt request is disabled
- b6 RIE - Receive Interrupt Enable - RXI and ERI interrupt requests are disabled
- b5 TE - Transmit Enable - Serial transmission is disabled
- b4 RE - Receive Enable - Serial reception is disabled
- b2 TEIE - Transmit End Interrupt Enable - A TEI interrupt request is disabled */
- SCI0.SCR.BYTE = 0x00;
- while (0x00 != (SCI0.SCR.BYTE & 0xF0))
- {
- /* Confirm that bit is actually 0 */
- }
- /* ---- Set the I/O port functions ---- */
- /* Set port output data - High level */
- PORT2.PODR.BIT.B0 = 1;
- /* Set port direction - TXDn is output port, RXDn is input port */
- PORT2.PDR.BIT.B0 = 1;
- PORT2.PDR.BIT.B1 = 0;
- /* Set port mode - Use pin as general I/O port */
- PORT2.PMR.BIT.B1 = 0;
- PORT2.PMR.BIT.B0 = 0;
- /* PWPR - Write-Protect Register
- b7 B0WI - PFSWE Bit Write Disable - Writing to the PFSWE bit is enabled
- b6 PFSWE - PFS Register Write Enable - Writing to the PFS register is enabled
- b5:b0 Reserved - These bits are read as 0. The write value should be 0. */
- MPC.PWPR.BIT.B0WI = 0;
- MPC.PWPR.BIT.PFSWE = 1;
- /* PFS - Pin Function Control Register
- b3:b0 PSEL - Pin Function Select - RXDn, TXDn */
- MPC.P20PFS.BYTE = (0x0A);
- MPC.P21PFS.BYTE = (0x0A);
- /* Enable write protection */
- MPC.PWPR.BIT.PFSWE = 0;
- MPC.PWPR.BIT.B0WI = 1;
- /* Use pin as I/O port for peripheral functions */
- PORT2.PMR.BIT.B1 = 1;
- PORT2.PMR.BIT.B0 = 1;
- /* ---- Initialization of SCI ---- */
- /* Select an On-chip baud rate generator to the clock source */
- SCI0.SCR.BIT.CKE = 0;
- /* SMR - Serial Mode Register
- b7 CM - Communications Mode - Asynchronous mode
- b6 CHR - Character Length - Selects 8 bits as the data length
- b5 PE - Parity Enable - When transmitting : Parity bit addition is not performed
- When receiving : Parity bit checking is not performed
- b3 STOP - Stop Bit Length - 1 stop bits
- b2 MP - Multi-Processor Mode - Multi-processor communications function is disabled
- b1:b0 CKS - Clock Select - PCLK clock (n = 0) */
- SCI0.SMR.BYTE = 0x00;
- /* SCMR - Smart Card Mode Register
- b6:b4 Reserved - The write value should be 1.
- b3 SDIR - Transmitted/Received Data Transfer Direction - Transfer with LSB-first
- b2 SINV - Transmitted/Received Data Invert - TDR contents are transmitted as they are.
- Receive data is stored as it is in RDR.
- b1 Reserved - The write value should be 1.
- b0 SMIF - Smart Card Interface Mode Select - Serial communications interface mode */
- SCI0.SCMR.BYTE = 0xF2;
- /* SEMR - Serial Extended Mode Register
- b7:b6 Reserved - The write value should be 0.
- b5 NFEN - Digital Noise Filter Function Enable - Noise cancellation function
- for the RXDn input signal is disabled.
- b4 ABCS - Asynchronous Mode Base Clock Select - Selects 16 base clock cycles for 1-bit period
- b3:b1 Reserved - The write value should be 0. */
- SCI0.SEMR.BYTE = 0x00;
- /* BRR - Bit Rate Register
- Bit Rate: (25MHz/(64*2^(-1)*57600bps))-1=12.56 */
- SCI0.BRR = 13; /* 57600bps */
- //SCI0.BRR = 40; /* 19200bps */
- /* ---- Initialization of SCI interrupt ---- */
- /* SCI interrupt priority level is 1 */
- IPR(SCI0, ) = 1;
- /* Interrupt request is cleared (Edge interrupt) */
- IR(SCI0,RXI0) = 0;
- IR(SCI0,TXI0) = 0;
- /* 送受信許可 */
- SCI0.SCR.BIT.RIE = 1; //受信割込み
- SCI0.SCR.BIT.TIE = 1; //送信割込み
- SCI0.SCR.BIT.RE = 1;
- SCI0.SCR.BIT.TE = 1;
- }
- /*
- * データの送信
- */
- void SCI_put(unsigned char c)
- {
- //while(IR(SCI0,TXI0)==0) ;
- if(c=='\r' || c=='\n') {
- while(IR(SCI0,TXI0)==0) ;
- IR(SCI0,TXI0) = 0;
- SCI0.TDR = '\r';
- while(IR(SCI0,TXI0)==0) ;
- IR(SCI0,TXI0) = 0;
- SCI0.TDR = '\n';
- } else {
- while(IR(SCI0,TXI0)==0) ;
- IR(SCI0,TXI0) = 0;
- SCI0.TDR = c;
- }
- }
- /*
- * データの受信
- */
- /* SSR - Serial Status Register
- b7:b6 Reserved - The read value is undefined. The write value should be 1.
- b5 ORER - Overrun Error Flag - An overrun error has occurred
- b4 FER - Framing Error Flag - A framing error has occurred
- b3 PER - Parity Error Flag - A parity error has occurred */
- #define SSR_ERROR_FLAGS (0x38)
- int SCI_get (void)
- {
- int c;
- if((SCI0.SSR.BYTE & SSR_ERROR_FLAGS)!=0) { // 受信エラー
- c = SCI0.RDR; //ダミーリード
- SCI0.SSR.BYTE = (SCI0.SSR.BYTE & ~SSR_ERROR_FLAGS) | 0xC0; //エラーフラグクリア
- IR(SCI0,ERI0) = 0;
- return -1;
- }
- while(IR(SCI0,RXI0) == 0) ;
- c = SCI0.RDR;
- IR(SCI0,RXI0) = 0;
- return c;
- }
- /*
- * printf関数で使用
- */
- int _write(int file,char *ptr,int len)
- {
- int i;
- for(i=0;i<len;i++) {
- SCI_put(ptr[i]);
- }
- return len;
- }
- /*
- * scanf関数で使用
- */
- int _read (int file, char *ptr, int len)
- {
- *ptr = SCI_get();
- return 1;
- }
- void change_oscillation_PLL(void)
- {
- unsigned int i;
- /* ---- Enable write protection ---- */
- /* PRCR - Protect Register
- b15:b8 PRKEY - PRC Key Code - A5h
- (The write value should be A5h to permission writing PRCi bit)
- b7:b4 Reserved - The write value should be 0.
- b3 PRC3 - Protect Bit 3 - Write disabled
- b2 PRC2 - Protect Bit 2 - Write enabled
- b1 PRC1 - Protect Bit 1 - Write enabled
- b0 PRC0 - Protect Bit 0 - Write enabled */
- SYSTEM.PRCR.WORD = 0xA507;
- /* ---- Set the VRCR register ---- */
- SYSTEM.VRCR = 0x00;
- /* ---- Set the main clock oscillator drive capability ---- */
- /* MOFCR - Main Clock Oscillator Forced Oscillation Control Register
- b7 Reserved - The write value should be 0.
- b6 MOSEL - Main Clock Oscillator Switch - Resonator
- b5:b4 MODRV2 - Main Clock Oscillator Drive Capability Switch 2
- - 16 MHz to 20 MHz
- b3:b1 MODRV - Main Clock Oscillator Drive Capability Switch
- - 16 MHz to 20 MHz non-lead type ceramic resonator
- b0 Reserved - The write value should be 0. */
- SYSTEM.MOFCR.BYTE = (0x30); /* Drive capability : 20 MHz crystal resonator */
- /* ---- Set wait time until the main clock oscillator stabilizes ---- */
- /* MOSCWTCR - Main Clock Oscillator Wait Control Register
- b7:b5 Reserved - The write value should be 0.
- b4:b0 MSTS - Main Clock Oscillator Waiting Time
- - Wait time is 131072 cycles (approx. 6.55 ms). */
- SYSTEM.MOSCWTCR.BYTE = (0x0D); /* Wait control register : 131072 cycles (approx. 6.55 ms) */
- /* ---- Operate the main clock oscillator ---- */
- /* MOSCCR - Main Clock Oscillator Control Register
- b7:b1 Reserved - The write value should be 0.
- b0 MOSTP - Main Clock Oscillator Stop - Main clock oscillator is operating. */
- SYSTEM.MOSCCR.BYTE = 0x00;
- while (0x00 != SYSTEM.MOSCCR.BYTE)
- {
- /* Confirm that the written value can be read correctly. */
- }
- /* ---- Wait processing for the clock oscillation stabilization ---- */
- for(i=0;i<100;i++) nop();
- /* ---- Set the PLL division ratio and multiplication factor ---- */
- /* PLLCR - PLL Control Register
- b15:b13 Reserved - The write value should be 0.
- b12:b8 STC - Frequency Multiplication Factor Select
- - Frequency multiplication factor is multiply-by-10.
- b7:b2 Reserved - The write value should be 0.
- b1:b0 PLIDIV - PLL Input Frequency Division Ratio Select
- - PLL input division ratio is divide-by-2. */
- SYSTEM.PLLCR.WORD = (0x0901); /* Division ratio and multiplication factor : divide-by-2, multiply-by-10 */
- /* ---- Set wait time until the PLL clock oscillator stabilizes ---- */
- /* PLLWTCR - PLL Wait Control Register
- b7:b5 Reserved - The write value should be 0.
- b4:b0 PSTS - PLL Waiting Time
- - Wait time is 65536 cycles (approx. 655.36 us). */
- SYSTEM.PLLWTCR.BYTE = (0x09); /* Wait control register : 65536 cycles (approx. 655.36 us) */
- /* ---- Operate the PLL clock oscillator ---- */
- /* PLLCR2 - PLL Control Register 2
- b7:b1 Reserved - The write value should be 0.
- b0 PLLEN - PLL Stop Control - PLL is operating. */
- SYSTEM.PLLCR2.BYTE = 0x00;
- /* ---- Wait processing for the clock oscillation stabilization ---- */
- for(i=0;i<100;i++) nop();
- /* ---- Set the operating power control mode ---- */
- /* OPCCR - Operating Power Control Register
- b7:b5 Reserved - The write value should be 0.
- b4 OPCMTSF - Operating Power Control Mode Transition Status Flag
- b3 Reserved - The write value should be 0.
- b2:b0 OPCM - Operating Power Control Mode Select - High-speed operating mode */
- SYSTEM.OPCCR.BYTE = (0x00); /* High-speed operating mode */
- while (0 != SYSTEM.OPCCR.BIT.OPCMTSF)
- {
- /* Confirm that the operation power control mode transition completed. */
- }
- /* ---- Set the internal clock division ratio ---- */
- /* SCKCR - System Clock Control Register
- b31:b28 FCK - FlashIF Clock(FCLK) Select - divide-by-4
- b27:b24 ICK - System Clock (ICLK) Select - divide-by-2
- b23 PSTOP1 - BCLK Pin Output Control - disabled. (Fixed high)
- b22:b20 Reserved - The write value should be 0.
- b19:b16 BCK - External Bus Clock (BCLK) Select - divide-by-4
- b15:b12 Reserved - The write value should be 0001b.
- b10:b8 PCLKB - Peripheral Module Clock B(PCLKB) Select - divide-by-4
- b7:b4 Reserved - The write value should be 0001b.
- b3:b0 PCLKD - Peripheral Module Clock D(PCLKD) Select - divide-by-2 */
- SYSTEM.SCKCR.LONG = 0x21821211; /* ICLK,PCLKD: divide-by-2 PCLKB,BCLK,FCLK: divide-by-4 */
- while (0x21821211 != SYSTEM.SCKCR.LONG)
- {
- /* Confirm that the written value can be read correctly. */
- }
- /* ---- Set the BCLK pin output ---- */
- /* BCKCR - External Bus Clock Control Register
- b7:b1 Reserved - The write value should be 0.
- b0 BCLKDIV - BCLK Pin Output Select - divide-by-2 */
- SYSTEM.BCKCR.BYTE = 0x01;
- while (0x01 != SYSTEM.BCKCR.BYTE)
- {
- /* Confirm that the written value can be read correctly. */
- }
- /* ---- Set the internal clock source ---- */
- /* SCKCR3 - System Clock Control Register 3
- b15:b11 Reserved - The write value should be 0.
- b10:b8 CKSEL - Clock Source Select - PLL circuit is selected.
- b7:b1 Reserved - The write value should be 0. */
- SYSTEM.SCKCR3.WORD = (0x0400); /* PLL */
- while ((0x0400) != SYSTEM.SCKCR3.WORD)
- {
- /* Confirm that the written value can be read correctly. */
- }
- /* ---- Disable write protection ---- */
- /* PRCR - Protect Register
- b15:b8 PRKEY - PRC Key Code - A5h
- (The write value should be A5h to permission writing PRCi bit)
- b2 PRC2 - Protect Bit 2 - Write disabled
- b1 PRC1 - Protect Bit 1 - Write disabled
- b0 PRC0 - Protect Bit 0 - Write disabled */
- SYSTEM.PRCR.WORD = 0xA500;
- }
- void main(void)
- {
- int buf;
- change_oscillation_PLL(); //クロックソースPLL
- SCI_Init ();
- _write(0,"RS232C test program\n",20);
- _write(0,"use SCI0\n",9);
- while(1) {
- buf = SCI_get();
- SCI_put(buf);
- }
- }
08. b7:b4 Reserved - The write value should be 0001b.
236. b3:b0 PCLKD - Peripheral Module Clock D(PCLKD) Select - divide-by-2 */
237. SYSTEM.SCKCR.LONG = 0x21821211; /* ICLK,PCLKD: divide-by-2 PCLKB,BCLK,FCLK: divide-by-4 */
この記事を読むと、助けてくださって、ありがとうございました。一つの不明点があるのが。ビットレートを設置したいとき、pclkを事前設定することが必要です。RX210として、pclkb、pclkdがあります。シリアル通信なら、このpclkはpclkbですか？もしこのこのpclkはpclkbだったら。例えば使うクリックは内部50Mクリクなら、私はsckcrレジスタでpckb b11－b8 2分周を設定し、この時pclkbは25Mになりました。そして、シリアルモードレジスタｂ1－b0 CKSは４分周を設置したら、pclkbは6.25Mになりますか？この6.25Mのpclkbはpclkですか？この6.25Mはビットレートを決定しますか？教えていただければいいですか