-#define PIT_CMD_CTR0 0x00 /* Select PIT counter 0 */
-#define PIT_CMD_CTR1 0x40 /* Select PIT counter 1 */
-#define PIT_CMD_CTR2 0x80 /* Select PIT counter 2 */
+#define PIT_CMD_CTR0 0x00 /* Select PIT counter 0 */
+#define PIT_CMD_CTR1 0x40 /* Select PIT counter 1 */
+#define PIT_CMD_CTR2 0x80 /* Select PIT counter 2 */
+
+#define PIT_CMD_LATCH 0x00 /* Counter Latch Command */
+#define PIT_CMD_LOW 0x10 /* Access counter bits 7-0 */
+#define PIT_CMD_HIGH 0x20 /* Access counter bits 15-8 */
+#define PIT_CMD_BOTH 0x30 /* Access counter bits 15-0 in two accesses */