3069RF-ZTAT Datasheet, PDF (543/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

Bit 2
TEND
Description
0
Transmission is in progress
[Clearing conditions]
Software reads TDRE while it is set to 1, then writes 0 in the TDRE flag.
The DMAC or DTC writes data in TDR.
1
End of transmission
[Setting conditions]
(Initial value)
The chip is reset or enters standby mode.
The TE bit and FER/ERS bit are both cleared to 0 in SCR.
TDRE is 1 and ERS is 0 at a time 2.5 etu after the last bit of a 1-byte serial character
is transmitted (normal transmission).
Note: etu : Elementary Time Unit (time for transfer of 1 bit)
14.2.3 Serial Mode Register (SMR)
The function of SMR bit 7 is modified in smart card interface mode. This change also causes a
modification to the function of bits 1 and 0 in the serial control register (SCR).
Bit
Initial value
Read/Write
7
GM
0
R/W
6
5
CHR
PE
0
0
R/W R/W
4
O/E
0
R/W
3
STOP
0
R/W
2
MP
0
R/W
1
CKS1
0
R/W
0
CKS0
0
R/W
Bit 7—GSM Mode (GM): With the normal smart card interface, this bit is cleared to 0. Setting
this bit to 1 selects GSM mode, an additional mode for controlling the timing for setting the
TEND flag that indicates completion of transmission, and the type of clock output used. The
details of the additional clock output control mode are specified by the CKE1 and CKE0 bits in
the serial control register (SCR).
Bit 7
GM
0
1
Description
Normal smart card interface mode operation
The TEND flag is set 12.5 etu after the beginning of the start bit.
Clock output on/off control only.
GSM mode smart card interface mode operation
The TEND flag is set 11.0 etu after the beginning of the start bit.
Clock output on/off and fixed-high/fixed-low control.
(Initial value)
Rev. 5.0, 09/04, page 521 of 978