Datasheet
73S1215F Data Sheet  DS_1215F_003 
106 Rev. 1.4 
Block Guard Time Register (BGT): 0xFE16 Å 0x10 
This register contains the Extra Guard Time Value (EGT) most-significant bit. The Extra Guard Time 
indicates the minimum time between the leading edges of the start bit of consecutive characters. The 
delay is depends on the T=0/T=1 mode. Used in transmit mode. This register also contains the Block 
Guard Time (BGT) value. Block Guard Time is the minimum time between the leading edge of the start 
bit of the last character received and the leading edge of the start bit of the first character transmitted. 
This should not be set less than the character length. The transmission of the first character will be held 
off until BGT has elapsed regardless of the TX data and TX/RX control bit timing. 
Table 105: The BGT Register 
MSB   LSB 
EGT.8 –  – BGT.4 BGT.3 BGT.1 BGT.2 BGT.0 
Bit Symbol  Function 
BGT.7  EGT.8  Most-significant bit for 9-bit EGT timer. See EGT below. 
BGT.6 –  
BGT.5 –  
BGT.4 BGT.4 
Time in ETUs between the start bit of the last received character to start bit 
of the first character transmitted to the smart card. Default value is 22. 
BGT.3 BGT.3 
BGT.2 BGT.2 
BGT.1 BGT.1 
BGT.0 BGT.0 
Extra Guard Time Register (EGT): 0xFE17 Å 0x0C 
This register contains the Extra Guard Time Value (EGT) least-significant byte. The Extra Guard Time 
indicates the minimum time between the leading edges of the start bit of consecutive characters. The 
delay is depends on the T=0/T=1 mode. Used in transmit mode. 
Table 106: The EGT Register 
MSB   LSB 
EGT.7 EGT.6 EGT.5 EGT.4 EGT.3 EGT.1 EGT.2 EGT.0 
Bit Function 
EGT.7 
Time in ETUs between start bits of consecutive characters. In T=0 mode, the minimum is 
1. In T=0, the leading edge of the next start bit may be delayed if there is a break detected 
from the smart card. Default value is 12. In T=0 mode, regardless of the value loaded, the 
minimum value is 12, and for T=1 mode, the minimum value is 11. 
EGT.6 
EGT.5 
EGT.4 
EGT.3 
EGT.2 
EGT.1 
EGT.0 










