-set AT91_WDT_CR [expr ($AT91_WDT + 0x00)] ;# Watchdog Control Register
-set AT91_WDT_WDRSTT [expr (1 << 0)] ;# Restart
-set AT91_WDT_KEY [expr (0xa5 << 24)] ;# KEY Password
+set AT91_WDT_CR [expr {$AT91_WDT + 0x00}] ;# Watchdog Control Register
+set AT91_WDT_WDRSTT [expr {1 << 0}] ;# Restart
+set AT91_WDT_KEY [expr {0xa5 << 24}] ;# KEY Password
-set AT91_WDT_MR [expr ($AT91_WDT + 0x04)] ;# Watchdog Mode Register
-set AT91_WDT_WDV [expr (0xfff << 0)] ;# Counter Value
-set AT91_WDT_WDFIEN [expr (1 << 12)] ;# Fault Interrupt Enable
-set AT91_WDT_WDRSTEN [expr (1 << 13)] ;# Reset Processor
-set AT91_WDT_WDRPROC [expr (1 << 14)] ;# Timer Restart
-set AT91_WDT_WDDIS [expr (1 << 15)] ;# Watchdog Disable
-set AT91_WDT_WDD [expr (0xfff << 16)] ;# Delta Value
-set AT91_WDT_WDDBGHLT [expr (1 << 28)] ;# Debug Halt
-set AT91_WDT_WDIDLEHLT [expr (1 << 29)] ;# Idle Halt
+set AT91_WDT_MR [expr {$AT91_WDT + 0x04}] ;# Watchdog Mode Register
+set AT91_WDT_WDV [expr {0xfff << 0}] ;# Counter Value
+set AT91_WDT_WDFIEN [expr {1 << 12}] ;# Fault Interrupt Enable
+set AT91_WDT_WDRSTEN [expr {1 << 13}] ;# Reset Processor
+set AT91_WDT_WDRPROC [expr {1 << 14}] ;# Timer Restart
+set AT91_WDT_WDDIS [expr {1 << 15}] ;# Watchdog Disable
+set AT91_WDT_WDD [expr {0xfff << 16}] ;# Delta Value
+set AT91_WDT_WDDBGHLT [expr {1 << 28}] ;# Debug Halt
+set AT91_WDT_WDIDLEHLT [expr {1 << 29}] ;# Idle Halt
-set AT91_WDT_SR [expr ($AT91_WDT + 0x08)] ;# Watchdog Status Register
-set AT91_WDT_WDUNF [expr (1 << 0)] ;# Watchdog Underflow
-set AT91_WDT_WDERR [expr (1 << 1)] ;# Watchdog Error
+set AT91_WDT_SR [expr {$AT91_WDT + 0x08}] ;# Watchdog Status Register
+set AT91_WDT_WDUNF [expr {1 << 0}] ;# Watchdog Underflow
+set AT91_WDT_WDERR [expr {1 << 1}] ;# Watchdog Error