MCF548x Reference Manual, Rev. 3
24-12 Freescale Semiconductor

24.3.3.10 Priority Registers (PRIORn)

When the PTD Control register bit 15 is set to a logic one, the first 16 Priority Registers are used to set the

associated priority level of the corresponding task. The last 16 Priority registers are unused in this case.

When PTD[PCTL15] is set to zero, the 32 Priority registers are used to set the associtated priority level of

the corresponding initiator. Only one register is shown. At system reset, all bits are initialized to a logic

zero.

7 ASTRT Auto start. This bit can be set or cleared by the programmer at any time. This bit is also cleared
if the MDE encounters an error in the task. At system reset, this bit is cleared.Setting this bit
instructs the MDE to start the task indicated by the ASTSKNUM field once the current task
completes.
0 Task will not start at end of taskl
1 Task will start at end of task
6 HIPRITSKEN High-priority task enable. This bit can be set or cleared by the programmer at any time. This bit
enables the MDE to give priority to the enable task function over a running task. At system
reset, this bit is cleared.
0 Normal task enable control
1 High priority task enable control
5 HLDINITNUM Hold initiator number. This bit allows the initiator number to be set by the programmer and held
for the complete task. The MDE module can not overwrite the programmed initiator except for
the use of the always initiator which is contained in a separate control bit.
0 Allow the MDE module to update initiator number for task
1 Keep current initiator number
4 — Reserved.
3–0 ASTSKNUM Auto-start task number. These four bits contain the task number that will be auto-started when
the ASTRT control bit is set. At system reset, these bits are cleared.
76543210
RHLD0000 PRI
W
Reset00000000
Reg
Addr
MBAR + 0x803C (PR0), 0x803D (PR1), 0x803E (PR2), 0x803F (PR3), 0x8040 (PR4), 0x8041 (PR5),
0x8042 (PR6), 0x8043 (PR7), 0x8044 (PR8), 0x8045 (PR9), 0x8046 (PR10), 0x8047 (PR11), 0x8048 (PR12),
0x8049(PR13), 0x804A (PR14), 0x804B (PR15), 0x804C(PR16), 0x804D(PR17), 0x804E (PR18), 0x804F (PR19),
0x8050 (PR20), 0x8051 (PR21), 0x8052 (PR22), 0x8053 (PR23), 0x8054 (PR24), 0x8055 (PR25), 0x8056 (PR26),
0x8057 (PR27), 0x8058 (PR28), 0x8059 (PR29), 0x805A (PR30), 0x805B (PR31)

Figure 24-11. Priority Register

Table 24-9. TCRn Field Descriptions (Continued)

Bits Name Description