diff --git a/arch/avr/src/at90usb/at90usb_lowconsole.c b/arch/avr/src/at90usb/at90usb_lowconsole.c
index eb93dc5e283..053b053cac6 100644
--- a/arch/avr/src/at90usb/at90usb_lowconsole.c
+++ b/arch/avr/src/at90usb/at90usb_lowconsole.c
@@ -56,7 +56,7 @@
  * Private Definitions
  ******************************************************************************/
 
-/* Baud rate settings for normal and double speed settings  */
+/* Baud rate settings for normal and double speed modes  */
 
 #define AVR_NORMAL_UBRR1 \
   ((((BOARD_CPU_CLOCK / 16) + (CONFIG_USART1_BAUD / 2)) / (CONFIG_USART1_BAUD)) - 1)
@@ -100,13 +100,20 @@
 #    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
 #    define UART1_DOUBLE_SPEED 1
 #  endif
-#else
+#elif BOARD_CPU_CLOCK <= 16000000
 #  if CONFIG_USART1_BAUD <= 38400
 #    define AVR_UBRR1 AVR_NORMAL_UBRR1
 #  else
 #    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
 #    define UART1_DOUBLE_SPEED 1
 #  endif
+#else
+#  if CONFIG_USART1_BAUD <= 57600
+#    define AVR_UBRR1 AVR_NORMAL_UBRR1
+#  else
+#    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
+#    define UART1_DOUBLE_SPEED 1
+#  endif
 #endif
 
 /******************************************************************************
@@ -156,8 +163,8 @@ void usart1_reset(void)
   PORTD &= ~(1 << 2);
 
   /* Unconfigure BAUD divisor */
-  
-  UBRR1  = 0;
+
+  UBRR1 = 0;
 }
 #endif
 
@@ -237,7 +244,7 @@ void usart1_configure(void)
 
   /* Set the baud rate divisor */
 
-  UBRR1  = AVR_UBRR1;
+  UBRR1 = AVR_UBRR1;
 }
 #endif
 
diff --git a/arch/avr/src/atmega/atmega_lowconsole.c b/arch/avr/src/atmega/atmega_lowconsole.c
index af558faa0a5..e746f6e5dd9 100644
--- a/arch/avr/src/atmega/atmega_lowconsole.c
+++ b/arch/avr/src/atmega/atmega_lowconsole.c
@@ -55,7 +55,7 @@
  * Private Definitions
  ******************************************************************************/
 
-/* USART0 Baud rate settings for normal and double speed settings  */
+/* USART0 Baud rate settings for normal and double speed modes  */
 
 #define AVR_NORMAL_UBRR0 \
   (((((BOARD_CPU_CLOCK / 16) + (CONFIG_USART0_BAUD / 2)) / (CONFIG_USART0_BAUD)) - 1)
@@ -99,16 +99,23 @@
 #    define AVR_UBRR0 AVR_DBLSPEED_UBRR0
 #    define UART0_DOUBLE_SPEED 1
 #  endif
-#else
+#elif BOARD_CPU_CLOCK <= 16000000
 #  if CONFIG_USART0_BAUD <= 38400
 #    define AVR_UBRR0 AVR_NORMAL_UBRR0
 #  else
 #    define AVR_UBRR0 AVR_DBLSPEED_UBRR0
 #    define UART0_DOUBLE_SPEED 1
 #  endif
+#else
+#  if CONFIG_USART0_BAUD <= 57600
+#    define AVR_UBRR0 AVR_NORMAL_UBRR0
+#  else
+#    define AVR_UBRR0 AVR_DBLSPEED_UBRR0
+#    define UART0_DOUBLE_SPEED 1
+#  endif
 #endif
 
-/* USART1 Baud rate settings for normal and double speed settings  */
+/* USART1 Baud rate settings for normal and double speed modes  */
 
 #define AVR_NORMAL_UBRR1 \
   ((((BOARD_CPU_CLOCK / 16) + (CONFIG_USART1_BAUD / 2)) / (CONFIG_USART1_BAUD)) - 1)
@@ -152,13 +159,20 @@
 #    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
 #    define UART1_DOUBLE_SPEED 1
 #  endif
-#else
+#elif BOARD_CPU_CLOCK <= 16000000
 #  if CONFIG_USART1_BAUD <= 38400
 #    define AVR_UBRR1 AVR_NORMAL_UBRR1
 #  else
 #    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
 #    define UART1_DOUBLE_SPEED 1
 #  endif
+#else
+#  if CONFIG_USART1_BAUD <= 57600
+#    define AVR_UBRR1 AVR_NORMAL_UBRR1
+#  else
+#    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
+#    define UART1_DOUBLE_SPEED 1
+#  endif
 #endif
 
 /******************************************************************************
diff --git a/arch/avr/src/avr/up_dumpstate.c b/arch/avr/src/avr/up_dumpstate.c
index e9d0859e8ae..2e3af537bf3 100644
--- a/arch/avr/src/avr/up_dumpstate.c
+++ b/arch/avr/src/avr/up_dumpstate.c
@@ -123,35 +123,35 @@ static inline void up_registerdump(void)
 
   if (current_regs)
     {
-      lldbg("R%d: %02x %02x %02x %02x %02x %02x %02x %02x\n",
+      lldbg("R%02d: %02x %02x %02x %02x %02x %02x %02x %02x\n",
             0,
             current_regs[REG_R0],  current_regs[REG_R1],
             current_regs[REG_R2],  current_regs[REG_R3],
             current_regs[REG_R4],  current_regs[REG_R5],
             current_regs[REG_R6],  current_regs[REG_R7]);
 
-      lldbg("R%d: %02x %02x %02x %02x %02x %02x %02x %02x\n",
+      lldbg("R%02d: %02x %02x %02x %02x %02x %02x %02x %02x\n",
             8,
             current_regs[REG_R8],  current_regs[REG_R9],
             current_regs[REG_R10], current_regs[REG_R11],
             current_regs[REG_R12], current_regs[REG_R13],
             current_regs[REG_R14], current_regs[REG_R15]);
 
-      lldbg("R%d: %02x %02x %02x %02x %02x %02x %02x %02x\n",
+      lldbg("R%02d: %02x %02x %02x %02x %02x %02x %02x %02x\n",
             16,
             current_regs[REG_R16], current_regs[REG_R17],
             current_regs[REG_R18], current_regs[REG_R19],
             current_regs[REG_R20], current_regs[REG_R21],
             current_regs[REG_R22], current_regs[REG_R23]);
 
-      lldbg("R%d: %02x %02x %02x %02x %02x %02x %02x %02x\n",
+      lldbg("R%02d: %02x %02x %02x %02x %02x %02x %02x %02x\n",
             24,
             current_regs[REG_R24], current_regs[REG_R25],
             current_regs[REG_R26], current_regs[REG_R27],
             current_regs[REG_R28], current_regs[REG_R29],
             current_regs[REG_R30], current_regs[REG_R31]);
 
-      lldbg("PC: %02x%02x SP: %02x%02x SREG: %02x\n",
+      lldbg("PC:  %02x%02x  SP: %02x%02x SREG: %02x\n",
             current_regs[REG_PCH], current_regs[REG_PCL],
             current_regs[REG_SPH], current_regs[REG_SPL],
             current_regs[REG_SREG]);
@@ -192,7 +192,7 @@ void up_dumpstate(void)
 
   /* Get the limits on the interrupt stack memory */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 0
   istackbase = (uint16_t)&g_intstackbase;
   istacksize = (CONFIG_ARCH_INTERRUPTSTACK & ~3) - 4;