DMA
Controller
12-71
Peripherals
Figure 12–48. DMA Timing When Destination is an STRB, STRB0, STRB1, MSTRB Bus (Continued)
Cycles
(H1)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Rate
Source
IOSTRB
R1
R1
R1
R1
I
R2
R2
R2
R2
I
†
IOSTRB
bus
Cw
Cw
†
Destination
STRB0,
STRB1, or
MSTRB
bus
W1 W1 W1 W1
W2 W2 W2 W2
(3 + Cr + 2 + Cw) T + 0.5 (T – 1)†
Cw
Cw
(’C30 only)
Source
STRB bus
R1
R1
R1
I
R2
R2
R2
I
R3
R3
R3
I
Cr
Cr
Cr
(2 + Cr + 2 + Cw) + (2 + Cw + max[1, Cr – Cw + 1])
Destination
MSTRB
bus
W1 W1 W1 W1
W2 W2 W2 W2
W3 W3 W3 W3
(T–1)
Cw
Cw
Cw
Legend:
T
=
Number of transfers
W
=
Single-cycle writes
Cr
=
Source-read wait states
R
n
=
Multicycle reads
Cw = Destination-write wait states
W
n
=
Multicycle writes
R
=
Single-cycle reads
I
=
Internal register cycle
† Write followed by read incurs in one extra half-cycle.