Datasheet

84
AT89C5132
4173C–USB–07/04
Table 74. R3 Response Format (OCR Register)
Table 75. R4 Response Format (Fast I/O)
Table 76. R5 Response Format
Data Packet Format There are two types of data packets: stream and block. As shown in Figure 58, stream
data packets have an indeterminate length while block packets have a fixed length
depending on the block length. Each data packet is preceded by a Start bit: a low level
on MCMD line and succeeded by an End bit: a high level on MCMD line. Due to the fact
that there is no predefined end in stream packets, CRC protection is not included in this
case. The CRC protection algorithm for block data is a 16-bit CCITT polynomial.
Figure 58. Data Token Format
Bit Position 47 46 [45:40] [39:8] [7:1] 0
Width (Bits) 1 1 6327 1
Value ‘0’ ‘0’ ‘111111’ - ‘1111111’ ‘1’
Description
Start bit
Transmission
bit
Reserved
OCR
register
Reserved End bit
Bit Position 47 46 [45:40] [39:8] [7:1] 0
Width (Bits) 11 63271
Value ‘0’ ‘0’ ‘100111’ - - ‘1’
Description
Start bit
Transmission
bit
Command
Index
Argument CRC7 End bit
Bit Position 47 46 [45:40] [39:8] [7:1] 0
Width (Bits) 1 1 6327 1
Value ‘0’ ‘0’ ‘101000’ - - ‘1’
Description
Start bit
Transmission
bit
Command
Index
Argument CRC7 End bit
0 Content 1
Sequential Data
CRCBlock Data 0 Content 1
Block Length