ML51/ML54/ML56
Sep. 01, 2020
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ML51/M
L54
/M
L56
Series
Tec
hnical Reference
Manual
block guard time.
According to ISO7816-3, in T = 0 mode, software must fill T bit = 0 (real block guard time = 16.5) to
this field; in T = 1 mode, software must fill T bit = 1 (real block guard time = 22.5) to it.
In transmit direction, the smart card sends data to smart card host controller, first. After the period is
greater than (16.5 or 22.5, by T bit setting), the smart card host controller begin to send the data.
Block Guard Time
Last Receiver Data
Transmitter Data
Figure 6.10-6 Transmit Direction Block Guard Time Operation
In receive direction, the smart card host controller sends data to smart card, first. If the smart card
sends data to smart card host controller at the time which is less than (16.5 or 22.5, by T bit
setting),the block guard time interrupt BGTIF (ScnIS[3]) is generated when RXBGTEN (SCnCR1[5])
and BGTIEN (ScnIE[3]) are enabled.
Block Guard Time
Last Transmitter Data
Receiver Data
Figure 6.10-7 Receive Direction Block Guard Time Operation
Extra Guard Time is EGT (SCnEGT[7:0]),it only affects the data transmitted by smart card interface,
the format is shown as Figure 6.10-8.
Start
Start
D1
D2
D3
D4
D5
D6
D7
D8
P
EGT
Stop bit
Figure 6.10-8 Extra Guard Time Operation
