Activate freeze or thaw operations on VIO channel 1 (HPS IO bank 2 and bank 3) and monitor for completeness and the current state. These fields interact with the hardware state machine in the Freeze Controller. These fields can be accessed independent of the value of SRC1.VIO1 although they only have an effect on the VIO channel 1 freeze signals when SRC1.VIO1 is setup to have the hardware state machine be the freeze signal source. All fields are only reset by a cold reset (ignore warm reset).
Module Instance Base Address Register Address
sysmgr 0xFFD08000 0xFFD08058

Offset: 0x58

Access: RW

Important: To prevent indeterminate system behavior, reserved areas of memory must not be accessed by software or hardware. Any area of the memory map that is not explicitly defined as a register space or accessible memory is considered reserved.
Bit Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16


15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0



RO 0x2


RW 0x1

hwctrl Fields

Bit Name Description Access Reset
2:1 vio1state

Software reads this field to determine the current frozen/thawed state of the VIO channel 1 or to determine when a freeze/thaw request is made by writing the corresponding *REQ field in this register has completed. Reset by a cold reset (ignores warm reset).

Value Description
0x0 Transitioning from thawed state to frozen state.
0x1 Thawed state. I/Os behave as configured. I/Os must be configured by the Scan Manager before entering this state.
0x2 Frozen state. I/O configuration is ignored. Instead, I/Os are in tri-state mode with a weak pull-up. Scan Manager can be used to configure the I/Os while they are frozen.
0x3 Transitioning from frozen state to thawed state.
RO 0x2
0 vio1req

Requests hardware state machine to generate freeze signal sequence to transition between frozen and thawed states. If this field is read by software, it contains the value previously written by software (i.e. this field is not written by hardware).

Value Description
0x0 Requests a thaw (unfreeze) operation.
0x1 Requests a freeze operation.
RW 0x1