Z85C3010PSG Zilog, Z85C3010PSG Datasheet - Page 64

• Manufacturer Part Number: Z85C3010PSG
• Description: IC 10MHZ Z8500 CMOS SCC 40-DIP
• Manufacturer: Zilog
• Series: SCCr

Specifications of Z85C3010PSG

• Processor Type: Z80
• Features: Error Detection and Multiprotocol Support
• Speed: 10MHz
• Voltage: 5V
• Mounting Type: Through Hole
• Package / Case: 40-DIP (0.620", 15.75mm)
• Cpu Speed: 8MHz
• Digital Ic Case Style: DIP
• No. Of Pins: 40
• Supply Voltage Range: 5V
• Operating Temperature Range: 0°C To +70°C
• Svhc: No SVHC (18-Jun-2010)
• Base Number: 85
• Rohs Compliant: Yes
• Clock Frequency: 10MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 269-3934; Z85C3010PSG

UM010901-0601
The formulas relating the baud rate to the time-constant
and vice versa are shown below.
In these formulas, the BRG clock frequency (PCLK or
/RTxC) is in Hertz, the desired baud rate in bits/sec, Clock
Mode is 1 in sync modes, 1, 16, 32 or 64 in async mode
and the time constant is dimensionless. The example in
Table 3-1 assumes a 2.4576 MHz clock (from /RTxC) fac-
tor of 16 and shows the time constant for a number of pop-
ular baud rates.
For example:
.
Time Constant =
Baud Rate =
TC =
2 x (Clock Mode) x (Time Constant+ 2)
(2 x 16) x 150
2.4576 x 10
2 x (Clock Mode) x (Baud Rate)
Clock Frequency
Clock Frequency
10
6
6
-2
= 510
- 2
Other commonly used clock frequencies include 3.6846,
4.6080, 4.91520, 6.144, 7.3728, 9.216, 9.8304, 12.288,
14.7456, 19.6608 (units in MHz).
Initializing the BRG is done in three steps. First, the time-
constant is determined and loaded into WR12 and WR13.
Next, the processor must select the clock source for the
BRG by setting bit D1 of WR14. Finally, the BRG is en-
abled by setting bit D0 of WR14 to 1.
Note: The first write to WR14 is not necessary after a hard-
ware reset if the clock source is the /RTxC pin. This is be-
cause a hardware reset automatically selects the /RTxC
pin as the BRG clock source.
Table 3-1. Baud Rates for 2.4576 MHz Clock and 16x
Baud
Rate
38400
19200
9600
4800
2400
1200
600
300
150
SCC/ESCC Ancillary Support Circuitry
Clock Factor
Decimal
SCC™/ESCC™ User’s Manual
126
254
510
14
30
62
0
2
6
Time Constant
0000
0002
0006
000E
001E
003E
007E
00FE
01FE
Hex
3-3
3