Owner's manual

45
A/T8xC5121
4164G–SCR–07/06
Table 24. SCETU0 Register
SCETU0 (S:ACh, SCRS = 1)
Smart Card ETU Register 0
Reset Value = 0111 0100b
Table 25. SCGT1 Register
SCGT1 (S:B5h, SCRS = 1)
Smart Card Transmit Guard Time Register 1
Reset Value = XXXX XXX0b
Table 26. SCGT0 Register
SCGT0 (S:B4h, SCRS = 1)
Smart Card Transmit Guard Time Register 0
Reset Value = 0000 1100b
76543210
ETU7 ETU6 ETU5 ETU4 ETU3 ETU2 ETU1 ETU0
Bit
Number
Bit
Mnemonic Description
7-0 ETU[7:0]
ETU LSB
The Elementary Time Unit is (ETU[10:0] - 0.5*COMP)/f, where f is the Card CLK
frequency.
According to ISO7816, ETU[10:0] can be set between 11 and 2047.
The default reset value of ETU[10:0] is 372 (F = 372, D = 1).
76543210
–––––––GT8
Bit
Number
Bit
Mnemonic Description
7-1 –
Reserved
The value read from these bits is indeterminate. Do not change these bits .
0GT8
Transmit Guard Time MSB
Used together with the Transmit Guard Time LSB (see SCGT0 Register).
76543210
GT7GT6GT5GT4GT3GT2GT1GT0
Bit
Number
Bit
Mnemonic Description
7-0 GT[7:0]
Transmit Guard Time LSB
The minimum time between two consecutive start bits in transmit mode is
GT[8:0] * ETU.
According to ISO 7816, GT can be set between 11 and 266 (11 to 254+12 ETU).