GD32F403xx User Manual
518
Table 20-12. I/O mode commands (class 9)
Cmd
index
type
argument
Response
format
Abbreviation
Description
CMD39
ac
[31:16] RCA
[15] register write
flag
[14:8]
register
address
[7:0] register data
R4
FAST_IO
Used to write and read 8 bit
(register) data fields. The
command addresses a card
and a register and provides the
data for writing if the write flag
is set. The R4 response
contains data read from the
addressed register if the write
flag is cleared to 0. This
command accesses application
dependent registers which are
not defined in the MMC
standard.
CMD40
bcr
[31:0] stuff bits
R5
GO_IRQ_STAT
E
Sets the system into interrupt
mode
CMD52
adtc
[31] R/W Flag
[30:28]
Function
Number
[27] RAW Flag
[26] Stuff Bits
[25:9]
Register
Address
[8] Stuff Bits
[7:0]
Write
Data/Stuff Bits
R5
IO_RW_DIREC
T
The IO_RW_DIRECT is the
simplest means to access a
single register within the total
128K of register space in any
I/O function, including the
common I/O area (CIA). This
command reads or writes 1
byte
using
only
1
command/response pair. A
common use is to initialize
registers or monitor status
values for I/O functions. This
command is the fastest means
to read or write single I/O
registers, as it requires only a
single command/response pair.
CMD53
adtc
[31] R/W Flag
[30:28]
Function
Number
[27] Block Mode
[26] OP code
[25:9]
Register
Address
[8:0]
Byte/Block
IO_RW_EXTEN
DED
This command allows the
reading or writing of a large
number of I/O registers with a
single command.