z85c30 ZiLOG Semiconductor, z85c30 Datasheet - Page 18

• Manufacturer Part Number: z85c30
• Description: Cmos Scc Serial Communications Controller
• Manufacturer: ZiLOG Semiconductor

I/O Interface Capabilities
PS011705-0608
Input
BRG
System communication to and from the SCC is performed through the SCC’s register set.
There are sixteen Write registers and eight Read registers.
Table 1
functions.
Throughout this document, Write and Read registers are referenced with the following
notation:
For example,
WR4A
RR3
•
•
RXD
DPLL
Upper Byte (WR13)
Time Constant
IN
‘WR’ for Write Register
‘RR’ for Read Register
16-Bit Down Counter
and
1-Bit
Write Register 4 for channel A
Read Register 3 for either/both channels
Table 2
DPLL
Internal TXD
Lower Byte (WR12)
MUX
Time Constant
Figure 7. SCC Receive Data Path
list the SCC registers and provide a brief description of their
DPLL
OUT
NRZI Decode
DIV 2
To Transmit Section
Internal Data Bus
SYNC Register
& Zero Delete
Output
BRG
CMOS SCC Serial Communications Controller
MUX
10 X 19 Frame
14-Bit Counter
Hunt Mode (BISYNC)
Status FIFO
SDLC-CRC
3-Bit
Rec. Error FIFO
Register (8 bits)
I/O Data buffer
3 Byte Deep
Receive Shift
CRC Delay
Register
CPU/I/O
Checker
CRC
Product Specification
CRC Result
SYNC
CRC
Rec. Error Logic
Rec. Error FIFO
3 Byte Deep
Functional Description
14