cortexelf-v1: doodling with 1802 bits

Just some random ideas about how to manage the 1802

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/cortexelf-v1/Makefile b/src/cortexelf-v1/Makefile
index 77598ddace24dcc4c4aa4d30c347518d0308b513..d71575212da1812bbf26212d0e2610bf03f07995 100644 (file)
--- a/src/cortexelf-v1/Makefile
+++ b/src/cortexelf-v1/Makefile
@@ -72,6 +72,7 @@ ALTOS_SRC = \
        ao_flash_stm.c \
        ao_button.c \
        ao_event.c \
+       ao_1802.c \
        ao_lisp_lex.c \
        ao_lisp_mem.c \
        ao_lisp_cons.c \

diff --git a/src/cortexelf-v1/ao_1802.c b/src/cortexelf-v1/ao_1802.c
new file mode 100644 (file)
index 0000000..55e778d
--- /dev/null
+++ b/src/cortexelf-v1/ao_1802.c
@@ -0,0 +1,170 @@
+/*
+ * Copyright © 2017 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <ao.h>
+#include <ao_flip_bits.h>
+#include <ao_1802.h>
+#include <ao_exti.h>
+
+/* Signals muxed between 1802 and STM */
+uint8_t                MRD, TPB, TPA, MWR;
+
+/* Decoded address driven by TPA/TPB signals */
+uint16_t       ADDRESS;
+
+/* Decoded data, driven by TPB signal */
+uint8_t                DATA;
+
+/* Mux control */
+#define MUX_1802       0
+#define MUX_STM                1
+
+uint8_t                MUX_CONTROL;
+
+/* Signals driven by 1802 only */
+uint8_t                WAIT, CLEAR, Q, SC, N;
+uint8_t                DMA_IN, DMA_OUT, INTERRUPT;
+uint8_t                EF;
+
+static uint8_t ma_stm;
+
+uint8_t
+MA(void) {
+       if (MUX_CONTROL == MUX_1802)
+               return (ao_gpio_get_all(MA_PORT) >> MA_SHIFT) & 0xff;
+       else
+               return ma_stm;
+}
+
+static void
+MA_set(uint8_t ma) {
+       ao_gpio_set_mask(MA_PORT, ((uint16_t) ma) << MA_SHIFT, 0xff << MA_SHIFT);
+       ma_stm = ma;
+}
+
+static uint8_t data_stm;
+
+static uint8_t
+DATA_get(void) {
+       if (MUX_CONTROL == MUX_1802)
+               return ao_flip_bits[(ao_gpio_get_all(DATA_PORT) >> DATA_SHIFT) & 0xff];
+       else
+               return data_stm;
+}
+
+static void
+DATA_set(uint8_t data) {
+       ao_gpio_set_mask(DATA_PORT, ((uint16_t) ao_flip_bits[data]) << DATA_SHIFT, 0xff << DATA_SHIFT);
+       data_stm = data;
+}
+
+static uint8_t
+N_get(void) {
+       return (ao_gpio_get_all(N_PORT) >> N_SHIFT) & 0x7;
+}
+
+static uint8_t
+EF_get(void) {
+       return (ao_gpio_get_all(EF_PORT) >> EF_SHIFT) & 0xf;
+}
+
+static uint8_t
+Q_get(void) {
+       return ao_gpio_get(Q_PORT, Q_BIT, Q_PIN);
+}
+
+static uint8_t
+SC_get(void) {
+       static const uint8_t flip_sc[4] = { 0, 2, 1, 3 };
+       return flip_sc[(ao_gpio_get_all(SC_PORT) >> SC_SHIFT) & 3];
+}
+
+void
+mrd(uint8_t value) { MRD = value; }
+
+void
+mwr(uint8_t value) { MWR = value; }
+
+void
+tpb(uint8_t value) {
+       TPB = value;
+
+       /* Latch low address and data on rising edge of TPB */
+       if (TPB) {
+               ADDRESS = (ADDRESS & 0xff00) | MA();
+               DATA = DATA_get();
+               N = N_get();
+               ao_wakeup(&ADDRESS);
+       }
+}
+
+void
+tpa(uint8_t value) {
+       TPA = value;
+
+       /* Latch high address on rising edge of TPA */
+       if (TPA) {
+               ADDRESS = (ADDRESS & 0x00ff) | ((uint16_t) MA() << 8);
+               SC = SC_get();
+               if (SC == SC_EXECUTE)
+                       EF = EF_get();
+               ao_wakeup(&ADDRESS);
+       }
+}
+
+#define ao_1802_in(port, bit, callback) do {                           \
+               ao_enable_input(port, bit, 0);                          \
+               ao_exti_enable(port, bit);                              \
+               ao_exti_set_callback(port, bit, callback);              \
+               (*callback)();                                          \
+       } while (0)
+
+static void mrd_isr(void) { mrd(ao_gpio_get(MRD_PORT, MRD_BIT, MRD_PIN)); }
+static void mwr_isr(void) { mwr(ao_gpio_get(MWR_PORT, MWR_BIT, MWR_PIN)); }
+static void tpb_isr(void) { tpb(ao_gpio_get(TPB_PORT, TPB_BIT, TPB_PIN)); }
+static void tpa_isr(void) { tpa(ao_gpio_get(TPA_PORT, TPA_BIT, TPA_PIN)); }
+static void q_isr(void) { Q = Q_get(); }
+
+static void
+ao_set_1802(void)
+{
+       ao_gpio_set(MUX_PORT, MUX_BIT, MUX_PIN, 0);
+       ao_1802_in(MRD_PORT, MRD_BIT, mrd_isr);
+       ao_1802_in(MWR_PORT, MWR_BIT, mwr_isr);
+       ao_1802_in(TPB_PORT, TPB_BIT, tpb_isr);
+       ao_1802_in(TPA_PORT, TPA_BIT, tpa_isr);
+       MUX_CONTROL = MUX_1802;
+}
+
+static void
+ao_set_arm(void)
+{
+       ao_enable_output(MRD_PORT, MRD_BIT, MRD_PIN, 1);
+       ao_enable_output(MWR_PORT, MWR_BIT, MWR_PIN, 1);
+       ao_enable_output(TPB_PORT, TPB_BIT, TPB_PIN, 0);
+       ao_enable_output(TPA_PORT, TPA_BIT, TPA_PIN, 0);
+       ao_gpio_set(MUX_PORT, MUX_BIT, MUX_PIN, 1);
+       MUX_CONTROL = MUX_STM;
+}
+
+void
+ao_1802_control_init(void)
+{
+       ao_set_1802();
+
+       ao_1802_in(Q_PORT, Q_BIT, q_isr);
+       (void) MA_set;
+       (void) DATA_set;
+       (void) ao_set_arm;
+}

diff --git a/src/cortexelf-v1/ao_1802.h b/src/cortexelf-v1/ao_1802.h
new file mode 100644 (file)
index 0000000..daa49f6
--- /dev/null
+++ b/src/cortexelf-v1/ao_1802.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2017 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef _AO_1802_H_
+#define _AO_1802_H_
+
+/* Signals muxed between 1802 and STM */
+extern uint8_t         MRD, TPB, TPA, MWR;
+
+/* Decoded address driven by TPA/TPB signals */
+extern uint16_t                ADDRESS;
+
+/* Decoded data, driven by TPB signal */
+extern uint8_t         DATA;
+
+extern uint8_t         SC;
+
+#define SC_FETCH       0
+#define SC_EXECUTE     1
+#define SC_DMA         2
+#define SC_INTERRUPT   3
+
+#endif /* _AO_1802_H_ */