Rainbow Electronics AT89C51SND1C - Manual (Page 111)

111
AT8xC51SND1C
4109E–8051–06/03
Figure 71. (Multiple) Block Read Operation
As shown in Figure 72 and Figure 73 the data write operation uses a simple busy signal-
ling of the write operation duration on the data line (MDAT).
Figure 72. Sequential Write Operation
Figure 73. Multiple Block Write Operation
Figure 74. No Response and No Data Operation
Command Token Format As shown in Figure 75, commands have a fixed code length of 48 bits. Each command
token is preceded by a Start bit: a low level on MCMD line and succeeded by an End bit:
a high level on MCMD line. The command content is preceded by a Transmission bit: a
high level on MCMD line for a command token (host to card) and succeeded by a 7 - bit
CRC so that transmission errors can be detected and the operation may be repeated.
Command content contains the command index and address information or parameters.
Figure 75. Command Token Format
Data Block
MCMD
MDAT
Data Stop Operation Block Read Operation
CRC
Multiple Block Read Operation
Command Response Command Response
Data Block CRC Data Block CRC
Stop Command
Data Stream
MCMD
MDAT
Data Stop Operation Data Transfer Operation
Command Response Command Response
Stop Command
Busy
MCMD
MDAT
Data Stop Operation Block Write Operation
Multiple Block Write Operation
Busy Data Block CRC Data Block CRC
Command Response Command Response
Stop Command
Status Busy Status
Command MCMD
MDAT
No Data Operation No Response Operation
Command Response
0
Total Length = 48 bits
Content CRC 1 1