TR4 User Manual
87
www.terasic.com
March 30, 2017
T
T
h
h
e
e
E
E
X
X
T
T
_
_
P
P
L
L
L
L
_
_
C
C
T
T
R
R
L
L
I
I
P
P
P
P
a
a
r
r
a
a
m
m
e
e
t
t
e
e
r
r
S
S
e
e
t
t
t
t
i
i
n
n
g
g
Users can refer to the following
Table 5-2
to set the external clock generator for the output
frequency.
Table 5-2 EXT_PLL_CTRL Instruction Ports
clk1_set_wr/ clk2_set_wr/
clk3_set_wr
Output Frequency
(
MHz
)
Description
4’b0001
x
Clock Generator Disable
4’b0010
62.5
Setting External Clock Generator
4’b0011
75
4’b0100
100
4’b0101
125
4’b0110
150
4’b0111
156.23
4’b1000
187
4’b1001
200
4’b1010
250
4’b1011
312.5
4’b1100
625
Others
x
Setting Unchanged
T
T
h
h
e
e
E
E
X
X
T
T
_
_
P
P
L
L
L
L
_
_
C
C
T
T
R
R
L
L
I
I
P
P
T
T
i
i
m
m
i
i
n
n
g
g
D
D
i
i
a
a
g
g
r
r
a
a
m
m
In this reference design the output frequency is set to 62.5, 75 and 100 MHz with the following
timing diagrams illustrated below.
When the ext_pll_ctrl IP receives the ‘conf_wr’ signal, the user needs to define (clk1_set_wr,
clk2_set_wr and clk3_set_wr) to set the External Clock Generator. When the ext_pll_ctrl IP
receives the ‘conf_rd’ signal, it will read the value back to clk1_set_rd, clk2_set_rd, and
clk3_set_rd.
Write Timing Waveform:
As
BUTTON0
(the trigger source defined by Terasic) is pressed, the 'conf_wr' signal is on the
rising edge, serial data is transferred immediately with the 'conf_ready' signal in the transmission
period starting at falling edge level as shown in
Figure 5-3
. As the transfer is completed, the
‘conf_ready’ signal returns back to original state at high-level.
Summary of Contents for TR4
Page 1: ...TR4 User Manual 1 www terasic com March 30 2017 y94 ...
Page 45: ...TR4 User Manual 42 www terasic com March 30 2017 Figure 2 24 Clock Connections of the TR4 ...
Page 58: ...TR4 User Manual 55 www terasic com March 30 2017 Figure 2 31 R199 R201 Position on TR4 ...
Page 67: ...TR4 User Manual 64 www terasic com March 30 2017 Figure 3 7 Access DDR3 SO DIMM Memory ...