Memory Controller
MPC885 PowerQUICC Family Reference Manual, Rev. 2
15-44
Freescale Semiconductor
Figure 15-42. Early GPL5 Control
•
GPL0 can be controlled by an address line specified in MxMR[G0CLx]. To use this feature, set
G0H and G0L in the RAM word. For example, for a SIMM with multiple banks, this address line
can be used to switch between banks.
The state of GPL_x5 logic depends on the defined in
Table 15-16
. In the first clock cycle of the slave
access, GPL_x5 reflects the value of ORx[G5LS]; in subsequent cycles, its state is determined by G5T4
and G5T3 in the RAM word. If the UPMB controls slave access, ORx[G5LA] can be used to select the
active GPL_x5 signal. G5LS applies only to memory requests and not to RAM words executed by the
RUN
command, exception, or memory periodic timer requests.
Table 15-16. GPL_x5 Signal Behavior
Controlling Machine
OR
x RAM
Word
GPL_x5 Behavior at the Controlling Clock Edge
Memory
Access
Slave Access
Clock Cycle
G5LA
G5LS
G5T4
G5T3
GPCM
x
N/A
N/A
x
x
GPL_A5 and GPL_B5 do not change their value.
UPMA
First
x
0
x
x
GPL_A5 is driven low at the falling edge of GCLK1_50.
1
GPL_A5 is driven high at the falling edge of GCLK1_50.
Second, third...
x
x
0
x
GPL_A5 is driven low at the falling edge of GCLK2_50 in
the current UPM cycle.
1
x
GPL_A5 is driven high at the falling edge of GCLK2_50 in
the current UPM cycle.
x
0
GPL_A5 is driven low at the falling edge of GCLK1_50 in
the current UPM cycle.
x
1
GPL_A5 is driven high at the falling edge of GCLK1_50 in
the current UPM cycle.
CLKOUT/
GCLK1_50
GPL5
Clock Phase
1
2
3
4
TS
RAM Word 1
4
GCLK2_50
Value Controlled by G5T4 and G5T3 on UPM
Value
Controlled
by G5LS
1
2
3
RAM Word 2
4
Summary of Contents for PowerQUICC MPC870
Page 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Page 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
Page 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Page 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Page 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Page 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...