Preliminary
S3C2451X RISC MICROPROCESSOR
HSMMC CONTROLLER
21-29
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
PRESENT STATE REGISTER
This register contains the SD Command Argument.
Register Address
R/W Description Reset
Value
PRNSTS0 0X4AC00024
RO/ROC
Present State Register (Channel 0)
0x000A0000
PRNSTS1 0X4A800024
RO/ROC
Present State Register (Channel 1)
0x000A0000
Name Bit
Description
Initial
Value
[31:25]
Reserved
0
PRNT
CMD
[24]
CMD Line Signal Level
(RO)
This status is used to check the
CMD
line level to recover from errors, and for
debugging.
Note :
CMD
port is mapped to
SD0_CMD
pin
0
PRNT
DAT
[23:20]
DAT[3:0] Line Signal Level
(RO)
This status is used to check the
DAT
line level to recover from errors, and for
debugging. This is especially useful in detecting the busy signal level from
DAT
[0].
D23 : DAT[3]
D22 : DAT[2]
D21 : DAT[1]
D20 : DAT[0]
Note :
DAT
port is mapped to
SD0_DAT
pin
Line
State
PRNT
WP
[19]
Write Protect Switch Pin Level
(RO)
The Write Protect Switch is supported for memory and combo cards.
This bit reflects the
SDWP#
pin.
1 = Write enabled (
SDWP#
=1)
0 = Write protected (
SDWP#
=0)
Note :
SDWP#
port is mapped to
SD0_nWP
pin, In S3C2451 case, SD#_nWP port
is fixed to High.
1
PRNT
CD
[18]
Card Detect Pin Level
(RO)
This bit reflects the inverse value of the
SDCD#
pin. Debouncing is not performed on
this bit. This bit may be valid when
Card State Stable
is set to 1, but it is not
guaranteed because of propagation delay. Use of this bit is limited to testing since it
must be debounced by software.
1 = Card present (
SDCD#
=0)
0 = No card present (
SDCD#
=1)
Note :
SDCD#
port is mapped to
SD0_nCD
pin, In S3C2451 case,
SD2_nCD(Channel 2) port is fixed to LOW.
Line
State
STBL
CARD
[17]
Card State Stable
(RO)
This bit is used for testing. If it is 0, the
Card Detect Pin Level
is not stable. If this bit
is set to 1, it means the
Card Detect Pin Level
is stable. No Card state can be
detected by this bit is set to 1 and
Card Inserted
is set to 0. The
Software Reset
For All
in the
Software Reset
register shall not affect this bit.
1 = No Card or Inserted
0 = Reset or Debouncing
1
(After
Reset)
INSCA
RD
[16]
Card Inserted
(RO)
This bit indicates whether a card has been inserted. The Host Controller shall
debounce this signal so that the Host Driver will not need to wait for it to stabilize.
Changing from 0 to 1 generates a
Card Insertion
interrupt in the
Normal Interrupt
0