Motorola MPC8260 - Manual (Page 438)

13-8 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part IV. Communications Processor Module
RCCR bit Þelds are described in Table 13-3.
Bits 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Field TIME Ñ TIMEP DR1M DR2M DR1QP EIE SCD DR2QP
Reset 0000_0000_0000_0000
R/W R/W
Addr 0x119C4
Bits 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Field ERAM Ñ EDM1 EDM2 EDM3 EDM 4 DR3M DR4M DR3QP DEM12 DEM34 DR4QP
Reset 0000_0000_0000_0000
R/W R/W
Addr 0X119C6
Figure 13-3. RISC Controller Configuration Register (RCCR)
Table 13-3. RISC Controller Configuration Register Field Descriptions
Bits Name Description
0 TIME Timer enable. Enables the CP internal timer that generates a tick to the CP based on the value
programmed into the TIMEP Þeld. TIME can be modiÞed at any time to start or stop the scanning of
the RISC timer tables.
1 Ñ Reserved
2Ð7 TIMEP Timer period controls the CP timer tick. The RISC timer tables are scanned on each timer tick and
the input to the timer tick generator is the general system clock (133/166MHZ) divided by 1,024.
The formula is (TIMEP + 1)
´ 1,024 = (general system clock period). Thus, a value of 0 stored in
these bits gives a timer tick of 1 ´ (1,024) = 1,024 general system clocks and a value of 63
(decimal) gives a timer tick of 64 ´ (1,024) = 65,536 general system clocks.
8, 9,
24, 25 DRxM IDMAx request mode. Controls the IDMA request x (DREQx) sensitivity mode. DREQx is used to
activate IDMA channel x. See Section 18.7, ÒIDMA Interface Signals.Ó
0 DREQx is edge sensitive (according to EDMx).
1 DREQx is level sensitive.
10Р11,
14Р15,
26Р27,
30Р31 DRxQP IDMAx request priority. Controls the priority of DREQx relative to the communications controllers.
See Section 18.7, ÒIDMA Interface Signals.Ó
00 DREQx has more priority than the communications controllers (default).
01 DREQx has less priority than the communications controllers (option 2).
10 DREQx has the lowest priority (option 3).
11 Reserved
12 EIE External interrupt enable. When EIE is set, DREQ1 acts as an external interrupt to the CP.
ConÞgure as instructed in the download process of a Motorola-supplied RAM microcode package.
0 DREQ1 cannot interrupt the CP.
1 DREQ1 will interrupt the CP.
13 SCD Scheduler conÞguration. ConÞgure as instructed in the download process of a Motorola-supplied
RAM microcode package.
0 Normal operation.
1 Alternate conÞguration of the scheduler.