參數(shù)資料
型號(hào): MC9S08DV96CLL
廠商: Freescale Semiconductor
文件頁(yè)數(shù): 264/458頁(yè)
文件大?。?/td> 0K
描述: MCU 8BIT 96K FLASH 100-LQFP
標(biāo)準(zhǔn)包裝: 90
系列: S08
核心處理器: S08
芯體尺寸: 8-位
速度: 40MHz
連通性: CAN,I²C,LIN,SCI,SPI
外圍設(shè)備: LVD,POR,PWM,WDT
輸入/輸出數(shù): 87
程序存儲(chǔ)器容量: 96KB(96K x 8)
程序存儲(chǔ)器類型: 閃存
RAM 容量: 4K x 8
電壓 - 電源 (Vcc/Vdd): 2.7 V ~ 5.5 V
數(shù)據(jù)轉(zhuǎn)換器: A/D 24x12b
振蕩器型: 外部
工作溫度: -40°C ~ 85°C
封裝/外殼: 100-LQFP
包裝: 托盤
Chapter 14 Serial Communications Interface (S08SCIV4)
MC9S08DZ128 Series Data Sheet, Rev. 1
336
Freescale Semiconductor
Figure 14-12. SCI Baud Rate Generation
SCI communications require the transmitter and receiver (which typically derive baud rates from
independent clock sources) to use the same baud rate. Allowed tolerance on this baud frequency depends
on the details of how the receiver synchronizes to the leading edge of the start bit and how bit sampling is
performed.
The MCU resynchronizes to bit boundaries on every high-to-low transition, but in the worst case, there are
no such transitions in the full 10- or 11-bit time character frame so any mismatch in baud rate is
accumulated for the whole character time. For a Freescale Semiconductor SCI system whose bus
frequency is driven by a crystal, the allowed baud rate mismatch is about 4.5percent for 8-bit data format
and about 4 percent for 9-bit data format. Although baud rate modulo divider settings do not always
produce baud rates that exactly match standard rates, it is normally possible to get within a few percent,
which is acceptable for reliable communications.
14.3.2
Transmitter Functional Description
This section describes the overall block diagram for the SCI transmitter, as well as specialized functions
for sending break and idle characters. The transmitter block diagram is shown in Figure 14-2.
The transmitter output (TxD) idle state defaults to logic high (TXINV = 0 following reset). The transmitter
output is inverted by setting TXINV = 1. The transmitter is enabled by setting the TE bit in SCIxC2. This
queues a preamble character that is one full character frame of the idle state. The transmitter then remains
idle until data is available in the transmit data buffer. Programs store data into the transmit data buffer by
writing to the SCI data register (SCIxD).
The central element of the SCI transmitter is the transmit shift register that is either 10 or 11 bits long
depending on the setting in the M control bit. For the remainder of this section, we will assume M = 0,
selecting the normal 8-bit data mode. In 8-bit data mode, the shift register holds a start bit, eight data bits,
and a stop bit. When the transmit shift register is available for a new SCI character, the value waiting in
the transmit data register is transferred to the shift register (synchronized with the baud rate clock) and the
transmit data register empty (TDRE) status ag is set to indicate another character may be written to the
transmit data buffer at SCIxD.
If no new character is waiting in the transmit data buffer after a stop bit is shifted out the TxD pin, the
transmitter sets the transmit complete ag and enters an idle mode, with TxD high, waiting for more
characters to transmit.
SBR12:SBR0
DIVIDE BY
Tx BAUD RATE
Rx SAMPLING CLOCK
(16
× BAUD RATE)
BAUD RATE GENERATOR
OFF IF [SBR12:SBR0] = 0
BUSCLK
BAUD RATE =
BUSCLK
[SBR12:SBR0]
× 16
16
MODULO DIVIDE BY
(1 THROUGH 8191)
相關(guān)PDF資料
PDF描述
MC9S08DV96CLH MCU 8BIT 96K FLASH 64-LQFP
MC9S08DV96CLF MCU 8BIT 96K FLASH 48-LQFP
MC9S08DV32VLC MCU 8BIT 32K FLASH 32-LQFP
MC9S08DV32AVLC MCU 8BIT 32K FLASH 32-LQFP
MC9S08DV16VLC MCU 8BIT 16K FLASH 32-LQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC9S08DV96F2CLF 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Microcontrollers
MC9S08DV96F2CLH 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Microcontrollers
MC9S08DV96F2CLL 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Microcontrollers
MC9S08DV96F2MLF 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Microcontrollers
MC9S08DV96F2MLH 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Microcontrollers