CCU 3000-I, CCU 3001-I
, CCU 30 -I
CCU 3001, CCU 3001-I
2
Table 2–1: I C and IM bus interface registers
For example, the software has to work off the following
sequence (ACK =1) to read a 16-bit word from an I Cde-
2
vice address 10H (on condition that the bus is not ac-
tive):
Address
Function
2
2D0H(w)
generate I C start condition,
2
transfer Data as I C address,
and set ACK=1
–write 21H to
–write 0FFH to
–write 0FFH to
–read dev. address2D6H
–read 1. databyte 2D6H
–read 2. databyte 2D6H
2D0H
2D2H
2D4H
check
receive
FIFO empty flag
(bit 1, 2D7H) be-
fore read
2D1H(w)
2D2H(w)
same as above, ACK=0
2
output 8 I C Data bits,
set ACK=1
2D3H(w)
2D4H(w)
same as above, set ACK=0
2
output 8 I C Data bits,
set ACK=1,
Thevalue21Hinthefirststepresultsfromthedevicead-
dressinthe7MSBsandtheR/W-bit(read=1)intheLSB.
If the telegrams are longer, the software has to ensure
that neither the Control-Data-FIFO nor the Read-FIFO
can overflow.
2
generate I C stop condition
2D5H(w)
same as above,
set ACK=0
2D6H(r)
2D7H(r)
receive FIFO
status flags:
To write data to this device:
bit 0
bit 1
not used
–write 20H to
–write 1. databyte to
–write 2. databyte to
2D0H
2D2H
2D4H
1= receive
FIFO empty
bit 2
1= contr-data-
FIFO half full
bit 3
bit 4
bit 5
bit 6
bit 7
1= Bus busy
The bus activity starts immediately after the first write to
the Control-Data-FIFO. In the I C mode the transmis-
2
2
I C data ACK
sion can be synchronized by an artificial extension of the
Low phase of the clock line. Transmission is not contin-
ued until the state of the clock line is High once again.
Thus a slave (software slaves!) can adjust the transmis-
sion rate to its own abilities.
2
I C adr ACK
“OR”ed ACK
not used
2D8H(w)
2D9H(w)
2DAH(w)
generate IM-address field
generate 8 IM-data bits
2
The I C/IM bus interface is a pure Master system, Multi-
generate 8 IM-data bits and
the IM-stop condition
master busses are not realizable.
The ident, clock and data terminal pins have open-drain
outputs with weak pull-up transistors.
2DBH(w)
terminal select & speed
68
MICRONAS INTERMETALL
MICRONAS [ MICRONAS ]
