Tangential change

1 files changed, 10 insertions, 6 deletions

diff --git a/rs422lib/rsbus.c b/rs422lib/rsbus.c
index 4c0fcb2..2b548a6 100644
--- a/rs422lib/rsbus.c
+++ b/rs422lib/rsbus.c
@@ -10,6 +10,11 @@
 #define SYSRET (0xF0)

 #define INSREP (0x0F)

 

+// Maximum size of receive buffer

+#define RSMAX (20)

+

+#define CODE_LEN (6)

+

 unsigned char rs_rxbuf[RSMAX];

 unsigned char len;

 unsigned char pch;

@@ -17,7 +22,7 @@ rshdlr rxhdlr;
 enum rs_stat{REST,ST,ADDR,READ,DISCARD,ED,DED};

 enum rs_stat rs_st=REST;

 

-unsigned char rs_tx[20]={STBIT1,0,RSADDR,MACTYPE};

+unsigned char rs_tx[CODE_LEN+RS_MAX]={STBIT1,0,RSADDR,MACTYPE};

 volatile unsigned char tx_len;

 volatile unsigned char tx_pos=255;

 

@@ -36,6 +41,7 @@ __interrupt void USCI0TX_ISR(void)
    	   UCA0TXBUF = rs_tx[tx_pos++]; // TX next character

 }

 

+// Inline send for ISR

 #pragma FUNC_ALWAYS_INLINE(rsbus_w_irq)

 static __inline void rsbus_w_irq(unsigned char* buf,unsigned int len)

 {

@@ -46,8 +52,6 @@ static __inline void rsbus_w_irq(unsigned char* buf,unsigned int len)
 	tx_len=len+7;

 	unsigned int parity=MACTYPE^RSADDR;

 	rs_tx[1]=0; // Useless addr spec

-	rs_tx[2]=RSADDR;

-	rs_tx[3]=MACTYPE;

 	for (i=0;i<len;++i)

 		parity^=(rs_tx[4+i]=buf[i]);

 	rs_tx[4+len]=parity;

@@ -132,19 +136,19 @@ __interrupt void rsbus_rx(void)
 	}

 }

 

+// Send something to the rs422 bus

+// Length must not exceeds RS_MAX

 void rsbus_w(int addr,unsigned char* buf,unsigned int len)

 {

 	while (tx_pos < tx_len)		// This shouldn't happen

 		__delay_cycles(100);	// Race condition -> wait

 	unsigned int i;

-	if (len>14)

+	if (len>RS_MAX)

 		return;

 	RSOUT |= RSPIN;

 	tx_len=len+7;

 	unsigned int parity=addr^MACTYPE^RSADDR;

 	rs_tx[1]=addr; // Useless addr spec

-	rs_tx[2]=RSADDR;

-	rs_tx[3]=MACTYPE;

 	for (i=0;i<len;++i)

 		parity^=(rs_tx[4+i]=buf[i]);

 	rs_tx[4+len]=parity;