pt7a6632 ETC-unknow, pt7a6632 Datasheet - Page 39

• Manufacturer Part Number: pt7a6632
• Description: Pt7a6632 32-channel Hdlc Controller
• Manufacturer: ETC-unknow

PT019(05/02)
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Data Transmission and Reception Operation
In transmission, the PT7A6632 reads the first command buffer
according to the channel start address, judges status of buffer,
fetches the MODE and FILL/MASK information for the chan-
nel, then it reads the Next Buffer Start Address in the current
buffer. It goes to the next buffer to get Data Length/Buffer
Size, and data bytes to send the data out in according to mode
specified and update the status if necessary. The PT7A6632
Figure 29. Typical Linked Buffer Transmit Sequence
xxBE
xxBF
xx00
xx80
xx81
xx82
xx83
Activation
Tx CH31
Memory
Tx CH0
Tx CH1
Command Buffer
Next BF Addr.
Next BF Addr.
FILL/MASK
Data Buffer #3
Buffer Size
Command
MPTY=0
CF/P=0
Modes
1: ATTN goes high.
2: PT7A6632 reads activation byte (xx00).
3: PT7A6632 reads the first buffer s starting address (command
4: PT7A6632 resets ATACK after ATTN goes low.
5: PT7A6632 continues processing command or data buffers as
or data), then sets ATACK, & starts processing that buffer.
controlled by the status of each.
Data Processing Memory
Next BF Addr.
Next BF Addr.
Data Buffer #4
Data Buffer #1
Data Length
Buffer Size
MPTY=0
MPTY=0
39
CF/P=1
CF/P=0
PT7A6632 32-Channel HDLC Controller
processes channel by channel in this way. See figure 29 for
example.
In receiving, the PT7A6632 reads the command buffer of a
channel to locates the CPU-allocated buffers for received data
storage, and stores the processed data into the data buffer and
write the Data Length. It updates the Status of the completed
buffer if necessary. See figure 30 for example.
Next BF Addr.
Next BF Addr.
Data Buffer #2
Data Buffer #5
Data Length
Data Length
MPTY=0
MPTY=0
CF/P=1
CF/P=1
Data Sheet
Ver:2