CR16MCS9VJE8 National Semiconductor, CR16MCS9VJE8 Datasheet - Page 72

• Manufacturer Part Number: CR16MCS9VJE8
• Description: 16-Bit Microcontroller IC
• Manufacturer: National Semiconductor

Specifications of CR16MCS9VJE8

• Controller Family/series: CR16X
• Core Size: 16 Bit
• Program Memory Size: 64K X 8 Flash
• Digital Ic Case Style: PQFP
• No. Of Pins: 80
• Mounting Type: Surface Mount
• Clock Frequency: 25MHz
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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flag is automatically reset when software reads the character
from the UnRBUF register. The RSFT register is not user ac-
cessible.
18.2.2
The synchronous mode of the USART enables the device to
communicate with other devices using three communication
signals: transmit, receive, and clock. In this mode, data bits
are transferred synchronously with the USART clock signal.
Data bits are transmitted on the rising edges and received on
the falling edges of the clock signal, as shown in Figure34.
Synchronous Mode
16
16
1
1
Sample
Generator/Checker
Error Detection
2
2
Control and
Parity
3
3
Figure 33. USART Asynchronous Communication
STARTBIT
4
4
5
5
Figure 32. USART Block Diagram
6
6
DATABIT
7
7
Transmitter
8
8
Receiver
72
9
9
Sample
Sample
Data bytes are transmitted and received least significant bit
(LSB) first.
In the synchronous mode, the transmit shift register (TSFT)
and the transmit buffer (UnTBUF) double-buffer the data for
transmission. To transmit a character, a data byte is loaded
in the UnTBUF register. The data is then transferred to the
TSFT register. The TSFT register shifts out one bit of the cur-
rent character, LSB first, on each rising edge of the clock.
Baud Rate Generator
10
10
11
11
Sys_clk
12
12
13 14
13 14
Baud Clock
Baud clock
15 16
15 16
DATA (LSB)
1
1
RDXn
CKXn
TDXn