HD64570 HITACHI [Hitachi Semiconductor], HD64570 Datasheet - Page 206

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

5.3.2Byte Synchronous Mode
In byte synchronous mode, synchronization of characters is accomplished by adding a SYN
character pattern to the beginning of the transmit or receive data.
MSCI byte synchronous mode supports mono-sync, bi-sync, and external synchronous modes. In
mono- or bi-sync mode, a one- or two-byte SYN character pattern is added for synchronization,
respectively. In external synchronous mode, the SYNC line is activated for synchronization. Byte
synchronous mode is specified with the PRTCL2 PRTCL0 bits of mode register 0 (MD0).
The character format for byte synchronous mode is shown in figure 5.23.
SYNC = low level (receiver)
The SYN character pattern lengths for transmission and reception in byte synchronous mode are
listed in table 5.12.
Table 5.12 SYN Character Pattern Length in Byte Synchronous Mode
Synchronous Mode
Mono-sync
Bi-sync
External synchronous
Rev. 0, 07/98, page 190 of 453
Note: Data field and CRC fields are received from the least significant bit.
8 bits
Synchronization
SYN
pattern
8 bits
SYN
Figure 5.23 Character Format for Byte Synchronous Mode
For Transmission
1 byte
2 bytes
1 byte
Part to be transferred to the receive buffer
External synchronous mode
Bi-sync mode
Data field
Mono-sync mode
8 bits x N (N 1)
For Reception
1 byte
2 bytes
SYNC line used for synchronization
CRC
16 bits
CRC
Part to be
transmitted