Rainbow Electronics T89C5121 - Manual (Page 44)

44
A/T8xC5121
4164G–SCR–07/06
Table 22. SCRBUF Register
SCRBUF (S:AA read-only, SCRS = 1)
Smart Card Receive Buffer Register
Reset Value = 0000 0000b
Table 23. SCETU1 Register
SCETU1 (S:ADh, SCRS = 1)
Smart Card ETU Register 1
Reset Value = 0XXX X001b
7 6 5 4 3 2 1 0
– – – – – – – –
Bit
Number
Bit
Mnemonic Description
– –
Provides the byte received from the I/O pin when SCRI is set.
Bit ordering on the I/O pin depends on the Convention (see SCICR Register).
7 6 5 4 3 2 1 0
COMP – – – – ETU10 ETU9 ETU8
Bit
Number
Bit
Mnemonic Description
7 COMP
Compensation
Clear this bit when no time compensation is needed (i.e. when the ETU to Card
CLK period ratio is close to an integer with an error less than 1/4 of Card CLK
period).
Set this bit otherwise and reduce the ETU period by 1 Card CLK cycle for even
bits.
6-3 –
Reserved
The value read from these bits is indeterminate. Do not change these bits .
2-0 ETU[10:8]
ETU MSB
Used together with the ETU LSB (see SCETU0 Register).