Using timer to generate precise pulses

Other Parts Discussed in Thread: TM4C1294NCPDT, ENERGIA

Hello, 

I'm trying to use a TM4C1294NCPDT to generate very precise interrupt-driven pulses using the hardware timers, and I'm not having much luck. I have the following code in an Energia sketch to (I hope) set up Timer 0A in 16-bit mode driven by the PIOSC clock at 16 MHz (?) with a prescale to get 1 microsecond ticks, and the timer configured for one-shot operation with a load of 10000 to get a 10 ms pulse. One external interrupt turns output on starts the timer and the timer's interrupt stops the timer and turns the output off. 

The code I have is not working as I intended, and I'm not smart enough to understand the TM4C1294NCPDT's datasheet for the timers. A few pointers on what I'm doing wrong would be greatly appreciated. 

#include "Energia.h"
#include <driverlib/timer.h>
#include <driverlib/sysctl.h>

void setup()
{
	Serial.begin(19200);

	pinMode(PB_3, INPUT_PULLDOWN);
	pinMode(PD_3, OUTPUT);

	SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
	while (!SysCtlPeripheralReady(SYSCTL_PERIPH_TIMER0));
	TimerConfigure(TIMER0_BASE, TIMER_CFG_A_ONE_SHOT);
	TimerClockSourceSet(TIMER0_BASE, TIMER_CLOCK_PIOSC);
	TimerPrescaleSet(TIMER0_BASE, TIMER_A, 16);
	TimerIntRegister(TIMER0_BASE, TIMER_A, lightOff);
	//TimerIntEnable(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
	TimerLoadSet(TIMER0_BASE, TIMER_A, 10000);

	attachInterrupt(PB_3, lightOn, RISING);
}

void loop()
{

}

void lightOff()
{
	digitalWrite(PD_3, LOW);
	TimerDisable(TIMER0_BASE, TIMER_A);
	TimerIntDisable(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
}

void lightOn()
{
	digitalWrite(PD_3, HIGH);
	TimerEnable(TIMER0_BASE, TIMER_A);
	TimerIntEnable(TIMER0_BASE, TIMER_A);
}