m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 295

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

SERIAL I/O
11.4 Clock asynchronous serial I/O (UART) mode
Fig. 11.4.2 Transfer data format
11-40
Fig. 11.4.3 Example of transfer data format
Table 11.4.5 Each bit in transmit data
ST
Start bit
DATA
Character bit
PAR
Parity bit
SP
Stop bit
11.4.2 Transfer data format
The transfer data format can be selected from formats shown in Figure 11.4.2. Bits 4 to 6 at addresses
30
for both transmitter and receiver sides.
Figure 11.4.3 shows an example of transfer data format. Table 11.4.5 lists each bit in transmit data.
Transfer data length of 7 bits
Transfer data length of 8 bits
Transfer data length of 9 bits
16
, 38
• 1ST–8DATA–1PAR–1SP
Name
16
and B0
16
select the transfer data format. (See Figure 11.2.2.) Set the same transfer data format
ST
“L” signal equivalent to 1 character bit. This is added immediately before the character
bits. It indicates start of data transmission.
Transmit data which is set in the UARTi transmit buffer register.
A signal that is added immediately after the character bits in order to improve data
reliability. The level of this signal changes according to selection of odd/even parity
in such a way that the sum of “1”s in the sum of this bit and character bits is always
an odd or even number.
“H” level signal equivalent to 1 or 2 character bits. This is added immediately after
the character bits (or parity bit when parity is enabled). It indicates completion of
data transmission.
LSB
Transmit/Receive data
DATA (8 bits)
1ST—7DATA
1ST—7DATA
1ST—7DATA—1PAR— 1SP
1ST—7DATA—1PAR— 2SP
1ST—8DATA
1ST—8DATA
1ST—8DATA—1PAR— 1SP
1ST—8DATA—1PAR— 2SP
1ST—9DATA
1ST—9DATA
1ST—9DATA—1PAR— 1SP
1ST—9DATA—1PAR— 2SP
7905 Group User’s Manual Rev.1.0
MSB PAR SP
Time
Functions
1SP
2SP
1SP
2SP
1SP
2SP
ST
Next transmit/receive data
(When continuously
transferred)
ST
DATA : Character bit (Transfer data)
PAR : Parity bit
SP
: Start bit
: Stop bit