1cc10d37c5d82e88dfe56adafd6d84924f3465c6

LIN uart doesn't have them (?)

- fixed uart code to only trigger rxt if more pending
  characters are in the input buffer
- fixed uart-echo test code to not get stuck in
  endless loop upon receiving '\r'

Signed-off-by: Markus Lampert  <mlampert@telus.net>
Signed-off-by: Michel Pollet <buserror@gmail.com>

diff --git a/simavr/sim/avr_uart.c b/simavr/sim/avr_uart.c
index 9447ce35b18bec57038ef2168b80e754bedd9733..5e36863af50e9689112ea14c990e7983e76c7533 100644 (file)
--- a/simavr/sim/avr_uart.c
+++ b/simavr/sim/avr_uart.c
@@ -106,9 +106,9 @@ static uint8_t avr_uart_read(struct avr_t * avr, avr_io_addr_t addr, void * para
        // made to trigger potential watchpoints
        v = avr_core_watch_read(avr, addr);
 
-       // should always trigger that timer
-//     if (!uart_fifo_isempty(&p->input))
-       avr_cycle_timer_register_usec(avr, p->usec_per_byte, avr_uart_rxc_raise, p);
+       // trigger timer if more characters are pending
+       if (!uart_fifo_isempty(&p->input))
+               avr_cycle_timer_register_usec(avr, p->usec_per_byte, avr_uart_rxc_raise, p);
 
        return v;
 }
@@ -143,7 +143,8 @@ static void avr_uart_write(struct avr_t * avr, avr_io_addr_t addr, uint8_t v, vo
        if (addr == p->r_udr) {
                avr_core_watch_write(avr, addr, v);
 
-               avr_regbit_clear(avr, p->udrc.raised);
+               if ( p->udrc.vector)
+                       avr_regbit_clear(avr, p->udrc.raised);
                avr_cycle_timer_register_usec(avr,
                                p->usec_per_byte, avr_uart_txc_raise, p); // should be uart speed dependent
 
@@ -162,7 +163,7 @@ static void avr_uart_write(struct avr_t * avr, avr_io_addr_t addr, uint8_t v, vo
                if (avr_regbit_get(avr, p->txen))
                        avr_raise_irq(p->io.irq + UART_IRQ_OUTPUT, v);
        }
-       if (addr == p->udrc.enable.reg) {
+       if (p->udrc.vector && addr == p->udrc.enable.reg) {
                /*
                 * If enabling the UDRC interrupt, raise it immediately if FIFO is empty
                 */
@@ -177,7 +178,7 @@ static void avr_uart_write(struct avr_t * avr, avr_io_addr_t addr, uint8_t v, vo
                                avr_raise_interrupt(avr, &p->udrc);
                }
        }
-       if (addr == p->udrc.raised.reg) {
+       if (p->udrc.vector && addr == p->udrc.raised.reg) {
                // get the bits before the write
                //uint8_t udre = avr_regbit_get(avr, p->udrc.raised);
                uint8_t txc = avr_regbit_get(avr, p->txc.raised);
@@ -214,7 +215,8 @@ void avr_uart_reset(struct avr_io_t *io)
 {
        avr_uart_t * p = (avr_uart_t *)io;
        avr_t * avr = p->io.avr;
-       avr_regbit_set(avr, p->udrc.raised);
+       if (p->udrc.vector)
+               avr_regbit_set(avr, p->udrc.raised);
        avr_irq_register_notify(p->io.irq + UART_IRQ_INPUT, avr_uart_irq_input, p);
        avr_cycle_timer_cancel(avr, avr_uart_rxc_raise, p);
        avr_cycle_timer_cancel(avr, avr_uart_txc_raise, p);
@@ -279,12 +281,15 @@ void avr_uart_init(avr_t * avr, avr_uart_t * p)
        p->io.irq[UART_IRQ_OUT_XON].flags |= IRQ_FLAG_FILTERED;
 
        avr_register_io_write(avr, p->r_udr, avr_uart_write, p);
-       avr_register_io_write(avr, p->udrc.enable.reg, avr_uart_write, p);
        avr_register_io_read(avr, p->r_udr, avr_uart_read, p);
        // monitor code that reads the rxc flag, and delay it a bit
        avr_register_io_read(avr, p->rxc.raised.reg, avr_uart_rxc_read, p);
 
-       avr_register_io_write(avr, p->r_ucsra, avr_uart_write, p);
-       avr_register_io_write(avr, p->r_ubrrl, avr_uart_baud_write, p);
+       if (p->udrc.vector)
+               avr_register_io_write(avr, p->udrc.enable.reg, avr_uart_write, p);
+       if (p->r_ucsra)
+               avr_register_io_write(avr, p->r_ucsra, avr_uart_write, p);
+       if (p->r_ubrrl)
+               avr_register_io_write(avr, p->r_ubrrl, avr_uart_baud_write, p);
 }
 

diff --git a/tests/atmega88_uart_echo.c b/tests/atmega88_uart_echo.c
index 17be737040714781051140778c198125f424dd59..e65fd56b840ff649b2e8752a4c41efe7a709647b 100644 (file)
--- a/tests/atmega88_uart_echo.c
+++ b/tests/atmega88_uart_echo.c
@@ -37,8 +37,10 @@ const struct avr_mmcu_vcd_trace_t _mytrace[]  _MMCU_ = {
 };
 
 static int uart_putchar(char c, FILE *stream) {
-       if (c == '\r')
+#if 0 // don't want character translation for this test
+       if (c == '\n')
                uart_putchar('\r', stream);
+#endif
        loop_until_bit_is_set(UCSR0A, UDRE0);
        UDR0 = c;
        return 0;