M306H7MG-XXXFP Datasheet, PDF (247/329 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with DATA ACQUISITION CONTROLLER

M306H7MG-XXXFP/MC-XXXFP/FGFP
14. EXPANSION FUNCTION
14.7 8/4 Humming Decoder
8/4 humming decoder operates only by written the data which is 8/4 humming- encoded to 8/4 humming register
(address 021A16). 8/4 humming register consists of 16 bits, can decode two data at once. Can obtain the decoded
result by reading 8/4 humming register, and the decoded value and error information are output. Corrects and
outputs the decoded value for single error, and outputs only error information for double error. Decoded result is
shown in Figure 14.21 and humming 8/4 register composition is shown in Figure 14.22.
Humming data (2)
MSB
Humming data (1)
LSB MSB
LSB
Writing
Address
021A16
8/4 humming register
Reading
Error information
(2)
00
Error information
(1)
00
Decode value
Decode value
(2)
(1)
MSB
LSB MSB
LSB
“1” output when
single error
“1” output when single error
“1” output when double error
“1” output when double error
Figure 14.21 Decoded result
Humming 8/4 register
b15
b8 b7
b0
Symbol
Address
When reset
HM8
021A16
000016
Function
RW
8/4 humming decoder operates only by written the data which 8/4 humming-decoded to 8/4
humming register. Can obtain the decoded result by reading this register, and can decode 2
couples of data at the same time.
Figure 14.22 Humming 8/4 register composition
Rev.2.10 Oct 25, 2006 Page 247 of 326
REJ03B0152-0210