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MSM66591/ML66592 User's Manual
Chapter 15 Serial Port Functions
15.3 Operation of Serial Ports
15.3.1 Transmit Operation
<UART Normal Mode>
The receive operation in this mode is shared by SCI0 and SCI1.
The clock pulse (BRGn), generated by the baud rate generator (SnTM), is divided by 16
to generate the transmit shift clock (STnCLK) (refer to Figure 15-30).
The transmit circuit controls the transfer of transmit data synchronizing with STnCLK.
The transmit operation is started with a signal to write transmit data to SnBUF0,
(WSnBUF: write instruction to SnBUF0, for example, a signal that is output if "STB A,
SnBUF0" is executed) as a trigger.
If WSnBUF is generated, a transmit start signal (LSTnSF) is generated after 1 CLK
(master clock).
The content of SnBUF0 is transferred to the transmit register at the fall of LSTnSF.
At this time, the transmit operation starts, and the STnFREE signal that indicates
transmitting is set to "L" level.
Then a transmit interrupt (TXnREADY) request is generated synchronizing with the
signal (M1S1) that indicates the beginning of an instruction execution, and the interrupt
request flag (QSCIn) is set to "1". When STnFREE becomes "L" level, a start bit is
generated synchronizing with the fall of the next STnCLK, and the TXDn pin changes
from "H" to "L" level at the rising edge of next CLK.
Hereafter, transmit data (LSB first) and a parity bit are added according to the specifica-
tion of STnCON, and a stop bit is finally added, and a 1 frame transmission ends.
In the MSM66591/ML66592 serial port transmit circuit, SnBUF0 and the transmit
register have a double structure, so that the next data can be written to SnBUF0 during
a transmission.
In this case, when a 1 frame transmission ends with a stop bit, the start bit of the next
transmission is generated, and the TXDn pin becomes "L" level.
In this mode, the default level on the TXDn pin is "H" level (when the corresponding bit
of the port secondary function register = "1").
[Note] n = 0–4.
<UART Multiprocessor Communication Mode>
In UART multiprocessor communication mode, transmission is controlled by the same
timing as UART normal mode. The differences follow.
• An MPC bit ("1": address transmitted; "0": data transmitted) is added between the end
of data (MSB bit) and the parity bit.
Summary of Contents for ML66592
Page 15: ...Contents 12 ...
Page 17: ......
Page 18: ...Overview Chapter 1 1 ...
Page 19: ......
Page 30: ...Description of Pins Chapter 2 2 ...
Page 31: ......
Page 44: ...CPU Architecture Chapter 3 3 ...
Page 45: ......
Page 101: ...3 56 MSM66591 ML66592User sManual Chapter 3 CPU Architecture ...
Page 102: ...CPU Control Functions Chapter 4 4 ...
Page 103: ......
Page 111: ...4 8 MSM66591 ML66592User sManual Chapter 4 CPU Control Functions ...
Page 112: ...Memory Control Functions Chapter 5 5 ...
Page 113: ......
Page 117: ...5 4 MSM66591 ML66592User sManual Chapter 5 Memory Control Functions ...
Page 118: ...Port Functions Chapter 6 6 ...
Page 119: ......
Page 152: ...Output Pin Control Pin OE Chapter 7 7 ...
Page 153: ......
Page 155: ...7 2 MSM66591 ML66592User sManual Chapter 7 Output Pin Control Pin OE ...
Page 156: ...Clock Generation Circuit Chapter 8 8 ...
Page 157: ......
Page 160: ...Time Base Counter TBC Chapter 9 9 ...
Page 161: ......
Page 164: ...Watchdog Timer WDT Chapter 10 10 ...
Page 165: ......
Page 170: ...Flexible Timer FTM Chapter 11 11 11 ...
Page 171: ......
Page 213: ...11 42 MSM66591 ML66592User sManual Chapter 11 Flexible Timer FTM ...
Page 214: ...General Purpose 8 Bit Timer Function Chapter 12 12 ...
Page 215: ......
Page 223: ...12 8 MSM66591 ML66592User sManual Chapter 12 General Purpose 8 Bit Timer Function ...
Page 224: ...PWM Functions Chapter 13 13 ...
Page 225: ......
Page 244: ...Baud Rate Generator Functions Chapter 14 14 ...
Page 245: ......
Page 263: ...14 18 MSM66591 ML66592User sManual Chapter 14 Baud Rate Generator Functions ...
Page 264: ...Serial Port Functions Chapter 15 15 ...
Page 265: ......
Page 348: ...A D Converter Functions Chapter 16 16 ...
Page 349: ......
Page 381: ...16 32 MSM66591 ML66592User sManual Chapter 16 A D Converter Functions ...
Page 382: ...Transition Detector Functions Chapter 17 17 ...
Page 383: ......
Page 387: ...17 4 MSM66591 ML66592User sManual Chapter 17 Transition Detector Functions ...
Page 388: ...Peripheral Functions Chapter 18 18 ...
Page 389: ......
Page 392: ...External Interrupt Request Function Chapter 19 19 ...
Page 393: ......
Page 396: ...Interrupt Request Processing Function Chapter 20 20 ...
Page 397: ......
Page 407: ...20 10 MSM66591 ML66592User sManual Chapter 20 Interrupt Request Processing Function ...
Page 408: ...Bus Port Functions Chapter 21 21 ...
Page 409: ......
Page 413: ...21 4 MSM66591 ML66592User sManual Chapter 21 Bus Port Functions ...
Page 414: ...Expansion Port Chapter 22 22 ...
Page 415: ......
Page 420: ...Serial Port with FIFO SCI5 Chapter 23 23 ...
Page 421: ......
Page 431: ...23 10 MSM66591 ML66592User sManual Chapter 23 Serial Port with FIFO SCI5 ...
Page 432: ...RAM Monitor Function Chapter 24 24 ...
Page 433: ......
Page 441: ...24 8 MSM66591 ML66592User sManual Chapter 24 RAM Monitor Function ...
Page 442: ...25 Electrical Characteristics Chapter 25 ...
Page 443: ......
Page 458: ...Package Dimensions Chapter 26 26 ...
Page 459: ......
Page 461: ...26 2 MSM66591 ML66592User sManual Chapter 26 Package Dimensions ...
Page 462: ...Revision History Chapter 27 27 ...
Page 463: ......
Page 465: ...27 2 MSM66591 ML66592User sManual Chapter 27 Revision History ...