Altera cyclone V Technical Reference page 233

cv_5v4
2016.10.28
Bit
3
wkpullup
2
tristate
1
bushold
0
cfg
hioctrl
Used to drive freeze signals to HPS HIO bank (DDR SDRAM). All fields are only reset by a cold reset
(ignore warm reset). The following equation determines when the weak pullup resistor is enabled: enabled
= ~wkpullup | (CFF & cfg & tristate) where CFF is the value of weak pullup as set by IO configuration
Module Instance
sysmgr
Offset:
0x50
Access:
RW
System Manager
Send Feedback
Name
Controls weak pullup resistor
Value
0x0
0x1
Controls IO tri-state
Value
0x0
0x1
Controls bus hold circuit
Value
0x0
0x1
Controls IO configuration
Value
0x0
0x1
0xFFD08000
Description
Description
Weak pullup resistor enabled.
Weak pullup resistor enable controlled by IO
configuration.
Description
IO tri-state enabled.
IO tri-state controlled by IO configuration.
Description
Disable bus hold circuit.
Bus hold circuit controlled by IO configura‐
tion.
Description
Disable IO configuration (forced to a safe
value).
Enables IO configuration as previously
configured by software using the Scan
Manager.
Base Address
hioctrl
Access
Register Address
0xFFD08050
5-39
Reset
RW 0x0
RW 0x0
RW 0x0
RW 0x0
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