- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄376479 > 89LV55 (Atmel Corp.) 8-Bit Microcontroller with 20K Bytes Flash PDF資料下載
參數(shù)資料
| 型號： | 89LV55 |
| 廠商： | Atmel Corp. |
| 英文描述： | 8-Bit Microcontroller with 20K Bytes Flash |
| 中文描述： | 8位閃存微控制器20,000字節(jié) |
| 文件頁數(shù)： | 10/23頁 |
| 文件大?。?/td> | 595K |
| 代理商： | 89LV55 |
AT89LV55
4-202
Baud Rate Generator
Timer 2 is selected as the baud rate generator by setting
TCLK and/or RCLK in T2CON (Table 2). Note that the baud
rates for transmit and receive can be different if Timer 2 is
used for the receiver or transmitter and Timer 1 is used for
the other function. Setting RCLK and/or TCLK puts Timer 2
into its baud rate generator mode, as shown in Figure 4.
The baud rate generator mode is similar to the auto-reload
mode, in that a rollover in TH2 causes the Timer 2 registers
to be reloaded with the 16-bit value in registers RCAP2H
and RCAP2L, which are preset by software.
The baud rates in Modes 1 and 3 are determined by Timer
2’s overflow rate according to the following equation.
The Timer can be configured for either timer or counter
operation. In most applications, it is configured for timer
operation (CP/T2 = 0). The timer operation is different for
Timer 2 when it is used as a baud rate generator. Normally,
as a timer, it increments every machine cycle (at 1/12 the
oscillator frequency). As a baud rate generator, however, it
increments every state time (at 1/2 the oscillator fre-
quency). The baud rate formula is given below.
where (RCAP2H, RCAP2L) is the content of RCAP2H and
RCAP2L taken as a 16-bit unsigned integer.
Timer 2 as a baud rate generator is shown in Figure 4. This
figure is valid only if RCLK or TCLK = 1 in T2CON. Note
that a rollover in TH2 does not set TF2 and will not gener-
ate an interrupt. Note too, that if EXEN2 is set, a l-to-0 tran-
sition in T2EX will set EXF2 but will not cause a reload from
(RCAP2H, RCAP2L) to (TH2, TL2). Thus when Timer 2 is
in use as a baud rate generator, T2EX can be used as an
extra external interrupt.
Note that when Timer 2 is running (TR2 = 1) as a timer in
the baud rate generator mode, TH2 or TL2 should not be
read from or written to. Under these conditions, the Timer is
incremented every state time, and the results of a read or
write may not be accurate. The RCAP2 registers may be
read but should not be written to, because a write might
overlap a reload and cause write and/or reload errors. The
timer should be turned off (clear TR2) before accessing the
Timer 2 or RCAP2 registers.
Figure 5.
Timer 2 in Clock-Out Mode
Modes 1 and 3 Baud Rates
16
-----------------------------------------------------------
=
---------------------------------------
–
32
)
[
]
×
----------------------------------------------------------------------------------------------
=
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| 89S8252 | 8-Bit Microcontroller with 8K Bytes Flash |
| 8M052489 | 8m Class DC to AC Inverter |
| 8T26A | 8-Channel, 10-Bit ADC with I2C Compatible Interface in 20-Lead TSSOP; Package: TSSOP; No of Pins: 20; Temperature Range: Industrial |
| 8T95 | 8-Channel, 10-Bit ADC with I2C Compatible Interface in 20-Lead TSSOP; Package: TSSOP; No of Pins: 20; Temperature Range: Industrial |
| 8T96 | High Speed Hex 3-State Buffers/Inverters |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 89M6KDGG-1NDG | 制造商:Legacy Electronics Inc 功能描述:1GB ECC UNBUFFERED DDR333 - Bulk |
| 89N5078 | 制造商:undefined 功能描述: |
| 89N5083 | 制造商:SPC TECHNOL 功能描述: |
| 89NF3R7 | 功能描述:線繞電阻器 - 透孔 50watt 3.7ohm 5% RoHS:否 制造商:Bourns 電阻:10 Ohms 容差:5 % 功率額定值:7 W 溫度系數(shù):200 PPM / C 系列:FW 端接類型:Axial 工作溫度范圍:- 55 C to + 155 C 尺寸:9.5 mm Dia. x 26 mm L 封裝:Ammo 產(chǎn)品:Power Resistors Wirewound High Energy |
| 89NM1032 | 制造商: 功能描述: 制造商:undefined 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。