HD64570 HITACHI [Hitachi Semiconductor], HD64570 Datasheet - Page 39

• Manufacturer Part Number: HD64570
• Description: Serial Communications Adaptor
• Manufacturer: HITACHI [Hitachi Semiconductor]

1.7.7
The transmitter (figure 1.11) loads parallel data supplied from the data bus into a transmit FIFO
consisting of 32 eight-bit registers. Next, according to the selected transmission format, it moves
the data into a transmit shift register which converts them to serial data. Data are transmitted LSB
first.
TRB:
Async: Asynchronous mode
COP:
BOP:
‡ :
bit (1)
Stop
1
MSCI TX/RX buffer register
Byte-synchronous mode
Bit-synchronous mode
Transmit data flow
Transmitter
(32-byte FIFO)
Transmit shift
register (8)
Transmit
TRB
buffer
Figure 1.11 Block Diagram of the MSCI Transmitter
Async
(8)
Transmit controller
(1)
32-Stage
EOM/MP bit
command FIFO
Parity
Internal data bus
(1)
BOP, COP
Break send
Async
Transmit CRC
calculator (16)
Flag, abort, idle, or SYN
character transmission
TX pattern
register
'0' Insertion
COP,
BOP
COP, BOP
Numbers in parentheses are bit lengths.
From receiver
(local loop back,
auto echo)
Baud rate
generator
Rev. 0, 07/98, page 23 of 453
Encoder
(1)
To receiver
(local loop back)
TXD
TXC