RM0082
Miscellaneous registers (Misc)
Doc ID 018672 Rev 1
245/844
12.4.28 DDR_PAD
register
The DDR_PAD is a R/W register which configures the SSTL pad internal parameters.The
register bit assignments is given in the next table.
Table 181.
COMPCOR_3V3_CFG register bit assignments
COMPCOR_3V3_CFG Register
0x0EC
Bit
Name
Reset Value
Description
[31]
TQ
1’h0
It enables IDDq mode.
[30:24]
RASRC
7'h78
Writing code compensation parameter sample from the
compensation macro-cell during Read operating mode
(ref. Compensation cell operating mode table).
[23]
RFU
-
Reserved for future use (Write don’t care - Read return
zeros).
[16:22]
NASRC
7'h0
Copy of the code on compensation bus (Note that bit 30
of RASRC is mapped on bit 16 and so on)
[15:05]
RFU
-
Reserved for future use (Write don’t care - Read return
zeros).
[04]
COMPOK
1’h0
Valid code compensation (RO); field actives high in
normal mode when the measured code is available on
the compensation bus nasrc.
[03]
ACCURATE
1’h0
Compensation cell internal/external reference
resistance definition:
1’b0: Internal reference resistor
1’b1: External reference resistor: used to improve the
accuracy of compensation code value.
[02]
FREEZE
1’h0
Freeze command: when high freezes the current
calculated value of compensation bus.
[01]
COMPTQ
1’h1
Compensation cell internal command parameter (ref.
Compensation cell operating mode table)
[00]
COM PEN
1’h0
It selects macro_cell operating modes.
Table 182.
DDR_PAD register bit assignments
DDR_PAD Register
0x0F0
Bit
Name
Reset
Value
Description
[31:19]
RFU
-
Reserved for future use (Write don’t care - Read return
zeros).
[18:15]
DDR_SW-mode[3:0]
4’h0
When ‘0110’ the selection of DDR2/DDR (Low power)
is decided by SW. In all other cases, the selection is
decided by the value of DDR2_EN pad.