firmware/memory.x

@@ -1,7 +1,7 @@
 MEMORY
 {
-  RAM : ORIGIN = 0x01004000, LENGTH = 4K
-  FLASH : ORIGIN = 0x01000000, LENGTH = 12K
+  RAM : ORIGIN = 0x01002000, LENGTH = 4K
+  FLASH : ORIGIN = 0x01000000, LENGTH = 8K
 }
 
 REGION_ALIAS("REGION_TEXT", FLASH);

firmware/src/i2c.rs

@@ -44,7 +44,7 @@ impl AmlibI2c{
     }
 
     fn is_nack(&self) -> bool {
-        unsafe { read_reg::<u8>(self.base_addr + SR) & 0x02 == 0 }
+        unsafe { read_reg::<u8>(self.base_addr + SR) & 0x02 != 0 }
     }
 }
 
@@ -105,10 +105,6 @@ impl Read<SevenBitAddress> for AmlibI2c {
                 return Err(Error::Busy);
             }
 
-            // Set read ACK to 1. Should probably ideally be done in an init() function
-            // but it doesn't really matter
-            write_reg(self.base_addr + CR, 0x30u8);
-
             // START
             write_reg(self.base_addr + CR, 0x01u8);
 

firmware/src/main.rs

@@ -7,7 +7,6 @@ use core::{arch::asm, ptr::{write_volatile, read_volatile}};
 use core::fmt::Write;
 
 use embedded_hal::prelude::{_embedded_hal_blocking_i2c_Write, _embedded_hal_blocking_i2c_Read};
-use mcp4726::Status;
 use riscv_rt::entry;
 
 mod eth;
@@ -37,31 +36,19 @@ fn main() -> ! {
     //let mut buf = [0u8; 1];
     //i2c.read(0b110_0011, &mut buf);
 
-    let mut buf = [0u8; 8];
-    i2c.read(0x63, &mut buf[0..4]).unwrap();
-    writeln!(uart, "DAC Read before config: {:x}, {:x}, {:x}, {:x}", buf[0], buf[1], buf[2], buf[3]).unwrap();
-
 
     let mut dac = mcp4726::MCP4726::new(3);
-    writeln!(uart, "Reading DAC status").unwrap();
-    match dac.read_status(&mut i2c) {
-        Ok(status) => writeln!(uart, "Is ready? {}, device powered? {}", status.ready, status.device_powered).unwrap(),
-        Err(e) => {
-            writeln!(uart, "Error: {:?}", e).unwrap();
-            panic!();
-        }
-    }
-    writeln!(uart, "Configuring DAC").unwrap();
+    writeln!(uart, "Reading DAC status");
+    dac.read_status(&mut i2c).unwrap();
+    writeln!(uart, "Configuring DAC");
     dac.write_config(&mut i2c, mcp4726::Config {
-        vref_source: mcp4726::VRef::UnbufferedVDD,
+        vref_source: mcp4726::VRef::UnbufferedVRef,
         operation: mcp4726::PowerDown::NormalOperation,
         use_2x_gain: false,
     }).unwrap();
-    writeln!(uart, "Setting DAC").unwrap();
+    writeln!(uart, "Setting DAC");
     dac.write_dac(&mut i2c, 0x0800).unwrap();
 
-    i2c.read(0x63, &mut buf[0..4]).unwrap();
-    writeln!(uart, "DAC Read after config: {:x}, {:x}, {:x}, {:x}", buf[0], buf[1], buf[2], buf[3]).unwrap();
     loop {
         //eth::tranmsit();
         //writeln!(uart, "Hello world!");

gateware/main.py

@@ -122,7 +122,7 @@ class Core(Elaboratable):
         fw = load_firmware_for_mem()
 
         # Hook up memory space
-        self.rom = ROM(size_bytes=12288, data=fw)
+        self.rom = ROM(size_bytes=8192, data=fw)
         m.submodules.rom = self.rom
         # Problem: not sure to handle how we do byte vs word addressing properly
         # So doing this shift is a bit of a hacky way to impl anything