Zilog Z16C35 Manual de usuario descargar pdf (Pagina 65)

ISCC

User Manual

UM011002-0808

At this point, the other registers should be initialized as necessary. When all of this is com-

pleted the transmitter maybe enabled by setting bit 3 of WR5 to one. Now that the trans-

mitter is enabled the CRC generator maybe initialized by issuing the Reset Tx CRC

Generator command in WR0, bit 6-7.

4.3.2 Byte-Oriented Synchronous Receive

The CPU places the receiver in Hunt mode whenever transmission begins (or whenever a

data dropout has occurred and the hardware determines that resynchronization is neces-

sary). In Hunt mode, the receiver shifts a bit into the Receive Shift register and compares

the

contents of the Receive Shift register and with the sync character (stored in another

begins transferring bytes to the receive FIFO.

Once the sync character-oriented mode has been selected, any of the four sync character

length maybe selected: 6-bits, 8-bits, 12-bits, or 16-bits.

The

Table 4-7 shows the WR register bit setting for selecting sync character le

ngth.

Table 4-7. Sync Character Length Selection

The arrangement of the sync character in WR6 and WR7 is

shown in Figure 4-5.

5,6 select number of bits

per character

WR10 7 CRC preset value

Table 4–15. Sync Character Length Selection

Sync Length WR4,D5 WR4,D4 WR10,D0

6 bits 0 0 1

8 bits 0 0 0

12 bits 0 1 1

16 bits 0 1 0

Table 4–14. Transmitter Initialization in Character Oriented Mode

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Zilog Z16C35 Manual de usuario Pagina 65