113
Table 8.6
Single-Mode DMA Memory Write Cycle States (External Memory Space)
Single-Mode DMA Memory Write Cycle States
(External Memory Space)
Bits 15–8:
DWW7–DWW0
WAIT
Pin Input
Signal
External Memory
Space
DRAM Space
Multiplexed
I/O
0
Not sampled during
single-mode DMA
memory write cycle
*
Areas 1, 3–5,7: 1 state,
fixed
Areas 0, 2, 6: 1 state +
long wait state
Column address
cycle: 1 state,
fixed (short pitch)
4
wait state
from
WAIT
1
Sampled during
single-mode DMA
memory write cycle
(Initial value)
Areas 1, 3–5, 7: 2 states
+ wait state from
WAIT
Areas 0, 2, 6: 1 state +
long wait state + wait
state from
WAIT
Column address
cycle: 2
wait state from
WAIT
(long pitch)
Note:
*
Sampled in the address/data multiplexed I/O space.
8.2.4
Wait State Control Register 3 (WCR3)
Wait state control register 3 is a 16-bit read/write register that controls
WAIT
pin pull-up and the
insertion of long wait states. WCR3 is initialized to H'F800 by a power-on reset. It is not
initialized by a manual reset or in standby mode.
Bit:
15
14
13
12
11
10
9
8
Bit name:
WPU
A02LW1 A02LW0
A6LW1
A6LW0
—
—
—
Initial value:
1
1
1
1
1
0
0
0
R/W:
R/W
R/W
R/W
R/W
R/W
—
—
—
Bit:
7
6
5
4
3
2
1
0
Bit name:
—
—
—
—
—
—
—
—
Initial value:
0
0
0
0
0
0
0
0
R/W:
—
—
—
—
—
—
—
—
•
Bit 15 (Wait Pin Pull-Up Control (WPU)): WPU controls whether the
WAIT
pin is pulled up
or not. When cleared to 0, the pin is not pulled up; when set to 1, it is pulled up.
Bit 15: WPU
Description
0
WAIT
pin is not pulled up
1
WAIT
pin is pulled up
(Initial value)
Содержание HD6417032
Страница 21: ......
Страница 35: ...xiv ...
Страница 85: ...50 ...
Страница 101: ...66 ...
Страница 129: ...94 ...
Страница 135: ...100 ...
Страница 343: ...308 ...
Страница 369: ...334 ...
Страница 383: ...348 ...
Страница 475: ...440 ...
Страница 525: ...490 CK RAS CAS TRp TRc TRcc tRASD1 tRASD2 tCASD3 tCASD2 TRr tCSR Figure 20 18 Self Refresh ...
Страница 578: ...543 CK RAS CAS TRp TRc TRcc tRASD1 tRASD2 tCASD3 tCASD2 TRr tCSR Figure 20 62 Self Refresh ...
Страница 689: ...654 ...