Operation; Overview - Hitachi SH7750 Hardware Manual

Bit 2—Transmit End (TEND): The setting conditions for the TEND flag are as follows.
Bit 2: TEND
0
1
etu: Elementary Time Unit (time for transfer for 1 bit)
Bits 1 and 0—Reserved: Not used with the smart card interface.
17.3

Operation

17.3.1

Overview

The main functions of the smart card interface are as follows.
• One frame consists of 8-bit data plus a parity bit.
• In transmission, a guard time of at least 2 etu (elementary time unit: the time for transfer of one
bit) is left between the end of the parity bit and the start of the next frame.
• If a parity error is detected during reception, a low error signal level is output for a 1-etu period
10.5 etu after the start bit.
• If an error signal is detected during transmission, the same data is transmitted automatically
after the elapse of 2 etu or longer.
• Only asynchronous communication is supported; there is no synchronous communication
function.
Rev. 6.0, 07/02, page 710 of 986
Description
Transmission in progress
[Clearing condition]
•
When 0 is written to TDRE after reading TDRE = 1
Transmission has been ended
[Setting conditions]
•
Power-on reset, manual reset, standby mode, or module standby
•
When the TE bit in SCSCR1 is 0 and the FER/ERS bit is also 0
•
When the GM bit in SCSMR1 is 0, and TDRE = 1 and FER/ERS = 0
(normal transmission) 2.5 etu after transmission of a 1-byte serial
character
•
When the GM bit in SCSMR1 is 1, and TDRE = 1 and FER/ERS = 0
(normal transmission) 1.0 etu after transmission of a 1-byte serial
character
(Initial value)