X-Git-Url: http://git.kpe.io/?p=avr_bc100.git;a=blobdiff_plain;f=BaseMegaFirmware%2FGCC%2Fport_ext.c;fp=BaseMegaFirmware%2FGCC%2Fport_ext.c;h=40ff4ab274bfa51b4b59db17df30298f162c9090;hp=0000000000000000000000000000000000000000;hb=89173ec9cd6f33843bf27c45be0f2f9be3f5f0ce;hpb=7997f136b12114035265bd082c854bff95fd73dc

diff --git a/BaseMegaFirmware/GCC/port_ext.c b/BaseMegaFirmware/GCC/port_ext.c
new file mode 100644
index 0000000..40ff4ab
--- /dev/null
+++ b/BaseMegaFirmware/GCC/port_ext.c
@@ -0,0 +1,126 @@
+// Martin Thomas 4/2008
+
+#include <stdint.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#include "port_ext.h"
+
+// #include "mystdio.h"
+
+static uint8_t virtports[PORT_EXT_OUTPORTS] = { 
+	PORT_EXT_INIT0, 
+	PORT_EXT_INIT1, 
+	PORT_EXT_INIT2 
+};
+
+static inline void strobe_delay(void)
+{
+#if 0
+	// delay ca. 100ns @ 2V for 74x595, 1us for tests 
+	_delay_us(1);
+#else
+	// 1 cycle ca 130ns at 7,3MHz
+	asm volatile("nop"::);
+#endif
+}
+
+static inline void output_disable(void)
+{
+	PORT_EXT_PORT |= ( 1 << PORT_EXT_PIN_OE );
+}
+
+static inline void output_enable(void)
+{
+	PORT_EXT_PORT &= ~( 1 << PORT_EXT_PIN_OE );
+}
+
+static inline void pulse_latch(void)
+{
+	PORT_EXT_PORT |= ( 1 << PORT_EXT_PIN_LATCH );
+	strobe_delay();
+	PORT_EXT_PORT &= ~( 1 << PORT_EXT_PIN_LATCH );
+	strobe_delay();
+}
+
+static inline void pulse_clock(void)
+{
+	PORT_EXT_PORT |= ( 1 << PORT_EXT_PIN_CLK );
+	strobe_delay();
+	PORT_EXT_PORT &= ~( 1 << PORT_EXT_PIN_CLK );
+	strobe_delay();
+}
+
+static void shift_out(void)
+{
+	uint8_t i, bit;
+
+	// first bit shifted out is bit7 in virtports[PORT_EXT_OUTPORTS-1]
+	// - on BC100 this is for U205 Q7
+	// last bit shifted out is bit 0 in virtports[0]
+	// - on BC100 this is for U202 Q0
+	for ( i = PORT_EXT_OUTPORTS; i > 0; i-- ) {
+		// myprintf_P("Port %d = %d\n", i-1, virtports[i-1] );
+		for ( bit = 8; bit > 0; bit-- ) {
+			if ( virtports[i-1] & ( 1 << (bit-1) ) ) {
+				PORT_EXT_PORT |= ( 1 << PORT_EXT_PIN_DIN );
+			}
+			else {
+				PORT_EXT_PORT &= ~( 1 << PORT_EXT_PIN_DIN );
+			}
+			pulse_clock();
+		}
+	}
+	pulse_latch();
+}
+
+void port_ext_init(void) 
+{
+	PORT_EXT_PORT &= ~( 
+		( 1 << PORT_EXT_PIN_CLK ) |
+		( 1 << PORT_EXT_PIN_DIN)  |
+		( 1 << PORT_EXT_PIN_LATCH ) );
+	PORT_EXT_PORT |= ( 1 << PORT_EXT_PIN_OE );
+	PORT_EXT_DDR  |= (
+		( 1 << PORT_EXT_PIN_OE)   |
+		( 1 << PORT_EXT_PIN_CLK ) |
+		( 1 << PORT_EXT_PIN_DIN)  |
+		( 1 << PORT_EXT_PIN_LATCH ) );
+	// set inititial values before enabling outputs
+	// - on BC100 this is just for U202 since it's
+	//   the only 74x595 with switchable /OE
+	shift_out();
+	output_enable();
+	// since Q7' is low while output is disabled (low)
+	// (Philips 74HC(T)595 datasheet) another shift- 
+	// out has to be done to set the cascaded outputs
+	// - on BC100 this will set U201, U202 and U205 outputs
+	shift_out();
+}
+
+void port_ext_update(void)
+{
+	shift_out();
+}
+
+void port_ext_bit_clear( uint8_t port, uint8_t bit )
+{
+	if ( ( port < PORT_EXT_OUTPORTS ) && ( bit < 8 ) ) {
+		virtports[port] &= ~( 1 << bit );
+	}
+}
+
+void port_ext_bit_set( uint8_t port, uint8_t bit )
+{
+	if ( ( port < PORT_EXT_OUTPORTS ) && ( bit < 8 ) ) {
+		virtports[port] |= ( 1 << bit );
+	}
+}
+
+void port_ext_set( uint8_t port, uint8_t val )
+{
+	if ( port < PORT_EXT_OUTPORTS ) {
+		virtports[port] = val;
+	}
+}
+
+