ade7169f16 Analog Devices, Inc., ade7169f16 Datasheet - Page 121

• Manufacturer Part Number: ade7169f16
• Description: Single-phase Energy Measurement Ic With 8052 Mcu, Rtc And Lcd Driver
• Manufacturer: Analog Devices, Inc.

Preliminary Technical Data
possible.
Therefore, when Timer 2 is used to generate baud rates, the
timer increments every two clock cycles rather than every core
machine cycle as before. It increments six times faster than
Timer 1, and, therefore, baud rates six times faster are possible.
Because Timer 2 has 16-bit autoreload capability, very low baud
rates are still possible.
Timer 2 is selected as the baud rate generator by setting the
TCLK and/or RCLK in T2CON. The baud rates for transmit
UART Timer Generated Baud Rates
The high integer dividers in a UART block mean that high
speed baud rates are not always possible. Also, generating baud
rates requires the exclusive use of a timer, rendering it unusable
for other applications when the UART is required. To address
this problem, the ADE7169F16 has a dedicated baud rate timer
(UART Timer) specifically for generating highly accurate baud
rates. UART Timer can be used instead of Timer 1 or Timer 2
for generating very accurate high speed UART baud rates
including 115200. UART Timer also allows a much wider range
of baud rates to be obtained. In fact, every desired bit rate from
12 bps to 393216 bps can be generated to within an error of
±0.8%. UART Timer also frees up the other three timers,
allowing them to be used for different applications. A block
diagram of UART Timer is shown in Figure 79.
Modes 1 and 3 Baud Rate =
NOTE: AVAILABILITY OF ADDITIONAL
EXTERNAL INTERRUPT
TRANSITION
T2EX
DETECTOR
PIN
PIN
F
T2
CORE
16
1
× Timer 2 Overflow Rate
C/ T2 = 0
C/ T2 = 1
EXEN2
CONTROL
CONTROL
TR2
Figure 78. Timer 2, UART Baud Rates
EXF 2
Rev. PrD | Page 121 of 140
RCAP2L
(8 BITS)
TL2
TIMER 2
INTERRUPT
RCAP2H
(8 BITS)
TH2
and receive can be simultaneously different. Setting RCLK
and/or TCLK puts Timer 2 into its baud rate generator mode as
shown in Figure 78.
In this case, the baud rate is given by the formula
Two SFRs Enhanced Serial baud rate control SFR (SBAUDT,
0x9E) and UART Timer Fractional Divider SFR (SBAUDF,
0x9D) are used to control UART Timer. SBAUDT is the baud
rate control SFR; it sets up the integer divider (DIV) and the
extended divider (SBTH) for UART Timer.
FRACTIONAL
RELOAD
DIVIDER
Modes 1 and 3 Baud Rate =
OVERFLOW
16
TIMER 2
65536
(1 + SBAUDF/64)
Figure 79. UART Timer, UART Baud Rate
2
F
D IV+SBTH
RCAP
CORE
32
1
1
F
core
OVERFLOW
2
TIMER 1
0
2
H
0
0
UART Timer
Rx/Tx CLOCK
:
RCAP
1
Rx CLOCK
TIMER 1/TIMER 2
RCLK
TCLK
16
16
2
L
1
1
SMOD
Tx CLOCK
0
0
TIMER 1/TIMER 2
RX
CLOCK
TX
CLOCK
ADE7169F16
UARTBAUDEN
Rx CLOCK
Tx CLOCK