Cirrus Logic AN83 - Manual (Page 52)

AN83
52 AN83REV3
Manufacturing Date
This word is the adapter’s manufacture date encoded in 16 bits, YR-MO-DY format. (Must be initialized
by OEM before shipping adapter.)
Bits 15-9 Two Least-significant Digits of Year
Seven bits for a range of 00 to 99 decimal. A roll-over to 00 will be interpreted as the year
2000.
Bits 8-5 Month
Four bits for a range of 01 to 12.
Bits 4-0 Day
Five bits for a range of 01 to 31.
IEEE Physical Address (Copy)
This field is a copy of the three words at address 1Ch to 1Eh. (Must be initialized by OEM before shipping
adapter.)
16-bit Checksum
The checksum stored at the end of the block is the 2’s complement of the 16-bit sum of all the preceding
words in the Driver Configuration Block. (The drivers access the Configuration Block as 16-bit words.)
Any carry out of the 16th bit is ignored. Since this checksum value is calculated as the 2’s complement of
the sum of all the preceding words in the block, a total of 0 should result when the checksum value is added
to the sum of the previous words. (Must be initialized by OEM before shipping adapter.)
EISA ID
The two EISA words make up the 32-bit EISA Product Identification Code.
Low Word These 16 bits make up the 3-letter identifier string of the OEM’s EISA ID in 5-bit com-
pressed ASCII. (A = 00001, B = 00010, C = 00011, etc.)
Bits 7-0 High order 8 bits of 16-bit value
Bits 15-8 Low order 8 bits of 16-bit value
High Word These 16 bits make up the OEM’s product ID No.
The upper order 11 bits are the product ID number and the lower order 5 bits are the revision
number.
Bits 7-0 High order 8 bits of 16-bit value
Bits 15-8 Low order 8 bits of 16-bit value