AN2135SC Cypress Semiconductor Corp, AN2135SC Datasheet - Page 317

• Manufacturer Part Number: AN2135SC
• Description: IC MCU 8051 8K RAM 24MHZ 44QFP
• Manufacturer: Cypress Semiconductor Corp
• Series: EZ-USB®r

Specifications of AN2135SC

• Applications: USB Microcontroller
• Core Processor: 8051
• Program Memory Type: ROMless
• Controller Series: AN213x
• Ram Size: 8K x 8
• Interface: I²C, USB
• Number Of I /o: 8
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 44-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1308

where RCAP2H,RCAP2L is the content of RCAP2H and RCAP2L taken as a 16-bit unsigned
number.
The 32 in the denominator is the result of CLK24 being divided by 2 and the Timer 2 overflow
being divided by 16. Setting TCLK or RCLK to 1 automatically causes CLK24 to be divided
by 2, as shown in Figure C-6., instead of the 4 or 12 determined by the T2M bit in the
CKCON SFR.
To derive the required RCAP2H and RCAP2L values from a known baud rate, use the
equation:
When either RCLK or TCLK is set, the TF2 flag will not be set on a Timer 2 roll over, and the
T2EX reload trigger is disabled.
EZ-USB TRM v1.9
Table C-11. Timer 2 Reload Values for Common Serial port Mode 1 Baud Rates
Note: using rates that are off by 2.3% or more will not work in all systems.
Nominal
57600
38400
28800
19200
Rate
9600
4800
2400
Appendix C: 8051 Hardware Description
C/T2
0
0
0
0
0
0
0
Diviso
Baud Rate =
156
312
RCAP2H,RCAP2L =
13
20
26
39
78
r
Reload Val
FEC8
EC
D9
B2
F3
E6
64
32 x (65536 - RCAP2H,RCAP2L)
65536 -
2403.846
57692.31
28846.15
19230.77
9615.385
4807.692
CLK24
Actual
37500
Rate
32 x Baud Rate
CLK24
-2.34%
0.16%
0.16%
0.16%
0.16%
0.16%
0.16%
Error
C - 21