
15-40
MPC866 PowerQUICC Family User’s Manual
MOTOROLA
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
User-Programmable Machines (UPMs)
19
G4T3/W
AEN
General-purpose line 4 timing 3/wait enable. Function depends on the value of MxMR[GPLx4DIS].
G4T3
If MxMR[GPLx4DIS] = 0, G4T3 is selected.
0 The value of GPL4 at the falling edge of GCLK1_50 will be 0.
1 The value of GPL4 at the falling edge of GCLK1_50 will be 1.
WAEN
If MxMR[GPLx4DIS] = 1, WAEN is selected.
0 The UPWAITx function is disabled.
1 The logical value of the UPM-controlled external signals are frozen when UPWAITx is asserted.
UPWAITx is sampled on the falling edge of GCLK2_50. See
Figure 15-45. for more information.
20
G5T4
General-purpose line 5 timing 4. Denes the state of GPL5 during phase 1–3.
0 The value of GPL5 at the falling edge of GCLK2_50 will be 0.
1 The value of GPL5 at the falling edge of GCLK2_50 will be 1.
21
G5T3
General-purpose line 5 timing 3. Denes the state of GPL5 during phase 4.
0 The value of GPL5 at the falling edge of GCLK1_50 will be 0.
1 The value of GPL5 at the falling edge of GCLK1_50 will be 1.
22–23
—
Reserved, should be cleared.
24
LOOP
Loop. The rst RAM word in the RAM array where LOOP is 1 is recognized as the loop start word.
The next RAM word where LOOP is 1 is the loop end word. RAM words between the start and end
are dened as the loop. The number of times the UPM executes this loop is dened in the
corresponding loop eld of the MxMR.
0 The current RAM word is not the loop start word or loop end word.
1 The current RAM word is the start or end of a loop.
25
EXEN
Exception enable. If an external device asserts TEA or RESET, EXEN allows branching to an
exception pattern at the exception start address (EXS) at a xed address in the RAM array.
0 The UPM continues executing the remaining RAM words.
1 The current RAM word allows a branch to the exception pattern after the current cycle if an
exception condition is detected. The exception condition can be an external device asserting
TEA, HRESET, or SRESET.
26–27
AMX
Address multiplexing. Determines the source of A[0–31] at the falling edge of GCLK1_50.
00 A[0–31] is the non-multiplexed address. For example, column address.
01 Reserved.
10 A[0–31] is the address requested by the internal master multiplexed according to MxMR[AMx].
For example, row address.
11 A[0–31] is the contents of MAR. Used for example, during SDRAM mode initialization.
28
NA
Next address. Determines when the address is incremented during a burst access.
0 The address increment function is disabled
1 The address is incremented in the next cycle. In conjunction with the BRx[PS], the increment
value of A[28–31] and/or BADDR[28–30] at the falling edge of GCLK1_50 is as follows
If the accessed bank has a 32-bit port size, the value is incremented by 4.
If the accessed bank has a 16-bit port size, the value is incremented by 2.
If the accessed bank has an 8-bit port size, the value is incremented by 1.
Note: The value of NA is relevant only when the UPM serves a burst-read or burst-write request.
NA is reserved under other patterns.
29
UTA
UPM transfer acknowledge. Controls the state of TA sampled by the external bus interface in the
current memory cycle. TA is output at the rising edge of GCLK2_50.
0 TA is driven low on the rising edge of GCLK2_50. The bus master samples it low in the next clock
cycle.
1 TA is driven high on the rising edge of GCLK2_50.
Table 15-14. RAM Word Bit Settings (continued)
Bit
Name
Description