Multimedia Card Registers
18.5.1.4 SD_SYSTEST Register (offset = 128h) [reset = 0h]
SD_SYSTEST is shown in
and described in
This register is used to control the signals that connect to I/O pins when the module is configured in
system test (SYSTEST) mode for boundary connectivity verification. In SYSTEST mode, a write into
SD_CMD register will not start a transfer. The buffer behaves as a stack accessible only by the local host
(push and pop operations). In this mode, the Transfer Block Size (SD_BLK[10:0] BLEN bits) and the
Blocks count for current transfer (SD_BLK[31:16] NBLK bits) are needed to generate a Buffer write ready
interrupt (SD_STAT[4] BWR bit) or a Buffer read ready interrupt (SD_STAT[5] BRR bit) and DMA requests
if enabled.
Figure 18-40. SD_SYSTEST Register
31
30
29
28
27
26
25
24
Reserved
R-0h
23
22
21
20
19
18
17
16
Reserved
OBI
R-0h
R/W-0h
15
14
13
12
11
10
9
8
SDCD
SDWP
WAKD
SSB
D7D
D6D
D5D
D4D
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
7
6
5
4
3
2
1
0
D3D
D2D
D1D
D0D
DDIR
CDAT
CDIR
MCKD
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 18-23. SD_SYSTEST Register Field Descriptions
Bit
Field
Type
Reset
Description
31-17
Reserved
R
0h
16
OBI
R/W
0h
Out-of-band interrupt (OBI) data value.
0x0 = The out-of-band interrupt pin is driven low.
0x1 = The out-of-band interrupt pin is driven high.
15
SDCD
R/W
0h
Card detect input signal (SDCD) data value
0x0 = The card detect pin is driven low.
0x1 = The card detect pin is driven high.
14
SDWP
R/W
0h
Write protect input signal (SDWP) data value
0x0 = The write protect pin SDWP is driven low.
0x1 = The write protect pin SDWP is driven high.
13
WAKD
R/W
0h
Wake request output signal data value.
0x0(W) = The pin SWAKEUP is driven low.
0x0(R) = No action. Returns 0.
0x1(W) = The pin SWAKEUP is driven high.
0x1(R) = No action. Returns 1.
12
SSB
R/W
0h
Set status bit.
This bit must be cleared prior attempting to clear a status bit of the
interrupt status register (SD_STAT).
0x0(W) = Clear this SSB bit field. Writing 0 does not clear already
set status bits.
0x0(R) = No action. Returns 0.
0x1(W) = Force to 1 all status bits of the interrupt status register
(SD_STAT) only if the corresponding bit field in the Interrupt signal
enable register (SD_ISE) is set.
0x1(R) = No action. Returns 1.
3394
Multimedia Card (MMC)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated