Merge pull request #5 from wickerwaka/v2

New version of the PicoROM board. v1.5. Adds level shifters to the address inputs, protecting the RP2040 from 5V signals. Adds a reset pin that can be controlled from the picorom tool to allow resetting the target hardware.
wickerwaka · Jun 15, 2024 · c7d5f01 · c7d5f01
2 parents af12f37 + 371730b
commit c7d5f01
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Showing 54 changed files with 44,443 additions and 48,726 deletions.
diff --git a/.github/workflows/firmware.yml b/.github/workflows/firmware.yml
@@ -43,6 +43,8 @@ jobs:
           path: |
             build/PicoROM.elf
             build/PicoROM.uf2
+            build/PicoROM-1.2.elf
+            build/PicoROM-1.2.uf2
           if-no-files-found: error
 
   release:

diff --git a/docs/PicoROM_PCB.png b/docs/PicoROM_PCB.png
diff --git a/docs/PicoROM_Schematic.pdf b/docs/PicoROM_Schematic.pdf
diff --git a/docs/delay.py b/docs/delay.py
@@ -0,0 +1,31 @@
+import csv
+import matplotlib.pyplot as plt
+
+header = None
+prev = []
+rise = {}
+delays = []
+with open('166Mhz.csv') as fp:
+	reader = csv.reader(fp)
+	for row in reader:
+		if row[0].startswith(';'):
+			continue
+		if not header:
+			header = [x.strip() for x in row]
+			prev = [ 1 for _ in header[1:] ]
+			rise = dict(((x, 0) for x in header[1:]))
+			continue
+
+		for idx in range(len(prev)):
+			v = int(row[idx + 1])
+			name = header[idx+1]
+			if prev[idx] == 0 and v == 1:
+				rise[name] = float(row[0])
+				if name == 'D2':
+					a_rise = rise['A2']
+					delays.append((float(row[0]) - a_rise) * 1000000000)
+			prev[idx] = v
+
+print(max(delays))
+plt.hist(delays, bins=100)
+plt.show()
diff --git a/docs/pcb_small.png b/docs/pcb_small.png
diff --git a/firmware/CMakeLists.txt b/firmware/CMakeLists.txt
@@ -4,39 +4,57 @@ project(rom_emulator C CXX ASM)
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_CXX_STANDARD 17)
 pico_sdk_init()
-add_executable(PicoROM
-    main.cpp
-    pico_link.cpp
-    rom.cpp
-    comms.cpp
-)
 
-pico_set_float_implementation(PicoROM none)
-pico_set_double_implementation(PicoROM none)
+foreach(TARGET PicoROM PicoROM-1.2)
+    add_executable(${TARGET}
+        main.cpp
+        pico_link.cpp
+        rom.cpp
+        comms.cpp
+    )
+
+    pico_set_float_implementation(${TARGET} none)
+    pico_set_double_implementation(${TARGET} none)
+
+    pico_generate_pio_header(${TARGET} ${CMAKE_CURRENT_LIST_DIR}/data_bus.pio)
+    pico_generate_pio_header(${TARGET} ${CMAKE_CURRENT_LIST_DIR}/comms.pio)
+
+    pico_enable_stdio_usb(${TARGET} 1)
+    pico_enable_stdio_uart(${TARGET} 0)
+
+    pico_set_linker_script(${TARGET} ${CMAKE_CURRENT_LIST_DIR}/memmap_firmware.ld)
+
+    pico_add_extra_outputs(${TARGET})
+    target_link_libraries(${TARGET}
+        pico_stdlib
+        pico_multicore
+        hardware_flash
+        hardware_pio
+        pico_unique_id
+    )
+
+    pico_set_program_name(${TARGET} PicoROM)
+    pico_set_program_url(${TARGET} https://github.com/wickerwaka/PicoROM)
+endforeach()
+
+pico_set_program_version(PicoROM 1.5/1.5)
+pico_set_program_version(PicoROM-1.2 1.5/1.2)
 
 target_compile_definitions(PicoROM PRIVATE
     PICO_HEAP_SIZE=16
     PICO_STACK_SIZE=640
     PICO_CORE1_STACK_SIZE=4
     USB_MAX_ENDPOINTS=4
     PICO_STDIO_ENABLE_CRLF_SUPPORT=0
-    OUTPUT_BUFFER=1
-    ACTIVITY_LED=1
+    TCA_EXPANDER=1
 )
 
-pico_generate_pio_header(PicoROM ${CMAKE_CURRENT_LIST_DIR}/data_bus.pio)
-pico_generate_pio_header(PicoROM ${CMAKE_CURRENT_LIST_DIR}/comms.pio)
-
-pico_enable_stdio_usb(PicoROM 1)
-pico_enable_stdio_uart(PicoROM 0)
-
-pico_set_linker_script(PicoROM ${CMAKE_CURRENT_LIST_DIR}/memmap_firmware.ld)
+target_compile_definitions(PicoROM-1.2 PRIVATE
+    PICO_HEAP_SIZE=16
+    PICO_STACK_SIZE=640
+    PICO_CORE1_STACK_SIZE=4
+    USB_MAX_ENDPOINTS=4
+    PICO_STDIO_ENABLE_CRLF_SUPPORT=0
+    TCA_EXPANDER=0
+)
 
-pico_add_extra_outputs(PicoROM)
-target_link_libraries(PicoROM
-    pico_stdlib
-    pico_multicore
-    hardware_flash
-    hardware_pio
-    pico_unique_id
-)
diff --git a/firmware/data_bus.pio b/firmware/data_bus.pio
@@ -51,4 +51,16 @@ dis_out:
     jmp start
 en_out: 
     irq wait 0 rel
+
+wait_clear:
+    mov osr, pins
+    out x, 2
+    jmp !x wait_clear
+.wrap
+
+
+.program tca5405
+
+.wrap_target
+    out pins, 1
 .wrap
diff --git a/firmware/main.cpp b/firmware/main.cpp
@@ -14,6 +14,9 @@
 #include "rom.h"
 #include "comms.h"
 
+#if TCA_EXPANDER
+bi_decl(bi_program_feature("Reset"));
+#endif
 
 static constexpr uint FLASH_ROM_OFFSET = FLASH_SIZE - ROM_SIZE;
 static constexpr uint FLASH_CFG_OFFSET = FLASH_ROM_OFFSET - FLASH_SECTOR_SIZE;
@@ -104,14 +107,70 @@ void configure_address_pins(uint32_t mask)
 
 static uint8_t identify_request = 0;
 
-#if ACTIVITY_LED==1
 repeating_timer_t activity_timer;
 
 static uint8_t identify_ack = 0;
 static uint8_t activity_cycles = 0;
 static uint8_t activity_duty = 0;
 static uint8_t activity_count = 0;
 
+static uint8_t link_cycles = 0;
+static uint8_t link_duty = 0;
+static uint8_t link_count = 0;
+
+#if TCA_EXPANDER
+bool activity_timer_callback(repeating_timer_t * /*unused*/)
+{
+    if (activity_count >= activity_cycles)
+    {
+        bool rom_access = rom_check_oe();
+
+        activity_cycles = 0;
+        activity_duty = 0;
+
+        if (rom_access)
+        {
+            activity_cycles = 5;
+            activity_duty = 1;
+        }
+
+        activity_count = 0;
+    }
+
+    if (link_count >= link_cycles)
+    {
+        bool identify_req = identify_request != identify_ack;
+        bool usb_activity = pl_check_activity();
+
+        link_cycles = 0;
+        link_duty = 0;
+
+        if (identify_req)
+        {
+            identify_ack++;
+            link_cycles = 100;
+            link_duty = 90;
+        }
+        else if (usb_activity)
+        {
+            link_cycles = 20;
+            link_duty = 10;
+        }
+
+        link_count = 0;
+    }
+
+    tca_set_pin(TCA_LINK_PIN, link_count < link_duty);
+    tca_set_pin(TCA_READ_PIN, activity_count < activity_duty);
+
+    activity_count++;
+    link_count++;
+
+    return true;
+}
+
+#else
+
 bool activity_timer_callback(repeating_timer_t * /*unused*/)
 {
     if (activity_count >= activity_cycles)
@@ -143,20 +202,13 @@ bool activity_timer_callback(repeating_timer_t * /*unused*/)
         activity_count = 0;
     }
 
-    if (activity_count >= activity_duty)
-    {
-        gpio_put(ACTIVITY_LED_PIN, false);
-    }
-    else
-    {
-        gpio_put(ACTIVITY_LED_PIN, true);
-    }
+    gpio_put(ACTIVITY_LED_PIN, activity_count < activity_duty);
 
     activity_count++;
 
     return true;
 }
-#endif // ACTIVITY_LED==1
+#endif // TCA_EXPANDER
 
 int main()
 {
@@ -168,15 +220,15 @@ int main()
 
     configure_address_pins(config.addr_mask);
 
-#if ACTIVITY_LED==1
     identify_ack = identify_request = 0;
 
+#if !TCA_EXPANDER
     gpio_init(ACTIVITY_LED_PIN);
     gpio_set_dir(ACTIVITY_LED_PIN, true);
     gpio_set_input_enabled(ACTIVITY_LED_PIN, false);
+#endif
 
     add_repeating_timer_ms(10, activity_timer_callback, nullptr, &activity_timer);
-#endif
 
     memcpy(rom_get_buffer(), flash_rom_data, ROM_SIZE);
 
@@ -312,6 +364,28 @@ int main()
                         break;
                     }
 
+                    case PacketType::Reset:
+                    {
+#if TCA_EXPANDER
+                        switch(req->payload[0])
+                        {
+                            case 'L':
+                                tca_set_pin(TCA_RESET_VALUE_PIN, false);
+                                tca_set_pin(TCA_RESET_PIN, true);
+                                break;
+
+                            case 'H':
+                                tca_set_pin(TCA_RESET_VALUE_PIN, true);
+                                tca_set_pin(TCA_RESET_PIN, true);
+                                break;
+
+                            default:
+                                tca_set_pin(TCA_RESET_PIN, false);
+                                break;
+                        }
+#endif // TCA_EXPANDER
+                    }
+
                     default:
                     {
                         pl_send_error("Unrecognized packet", req->type, req->size);

diff --git a/firmware/pico_link.h b/firmware/pico_link.h
@@ -23,6 +23,7 @@ enum class PacketType : uint8_t
 
     CommitFlash = 12,
     CommitDone = 13,
+    Reset = 14,
 
     CommsStart = 80,
     CommsEnd = 81,