
62
ECP5 and ECP5-5G Hi
g
h-Speed I/O Interface
Table 18. DDRDLLA Port List
Table 19. DDRDLL Attributes
DLL Delay (DLLDEL)
The DLLDEL receive delay codes from the DDRDLL and generates a delayed clock output.
The DLLDEL receives delay from the DDRDLL. The delayed clock output of the DLLDEL can be connected to the
IDDR module.
The delay from the DLLDEL can be dynamically adjusted using counter margin control signals that can shift the
delay up or down.DLLDELD
Figure 54. DLLDELD Primitive
Table 20. DLLDELD Port List
Port
I/O
Description
CLK
I
Reference clock input to the DDRDLL. Should run at the same frequency as the
clock to be delayed.
RST
I
Reset input to the DDRDLL
UDDCNTLN
I
Update control to update the delay code. When low, the delay code out of the
DDRDLL is updated. Should not be active during a read or a write cycle
FREEZE
I
Releases the DDRDLL input clock
DDRDEL
O
The delay codes from the DDRDLL to be used in DQSBUF or DLLDEL
LOCK
O
Lock output to indicate the DDRDLL has valid delay output
DCNTL [7:0]
O
The delay codes from the DDRDLL available for the user IP.
Attribute
Description
Values
Default
FORCE_MAX_DELAY
1
Bypass DLL locking procedure at low frequency
YES, NO
NO
1. When Fin is =<30 MHz. The software sets Force_max_delay to YES. DDRDLL will not go through the locking process but will be locked to
maximum delay steps under such conditions.
Port I/O
Description
A
I
Clock input
DDRDEL
I
Delay inputs from DDRDLL
LOADN
I
Used to reset back to 90° delay.
MOVE
I
Pulse is required to change delay settings. The value on Direction will be sam-
pled at the falling edge of MOVE.
DIRECTION
I
Indicates delay direction. ‘1’ to decrease delay and ‘0’ to increase delay
CFLAG
O
Indicates the delay counter has reached its maximum value when moving up or
minimum value when moving down.
Z
O
Delayed clock output
DLLDELD
Z
A
DDRDEL
LOADN
MOVE
DIRECTION
CFLAG