DS80CH11 Maxim, DS80CH11 Datasheet - Page 38

• Manufacturer Part Number: DS80CH11
• Description: The system energy manager is a highly integrated microcontroller that provides several key features for systems including key scanning and control, battery and power management, as well as two 2-Wire serial I/O Ports
• Manufacturer: Maxim

DATA TRANSFER ON EITHER 2–WIRE BUS Figure 6–3
6.3.1
In the master transmit mode, the SEM is configured as a
master device and transfers a number of data bytes to a
slave receiver. A timing diagram in Figure 6–4 illus-
trates the interaction between the firmware and hard-
ware with respect to events on the 2–Wire bus.
The master transmit mode can now be entered by set-
ting the STAx bit. The 2–Wire port logic will test the
2–Wire bus and generate a start condition as soon as
the bus is free. As soon as the start condition is trans-
MASTER TRANSMIT OPERATION TIMING Figure 6–4
SDAx
SCLx
DS80CH11
SDAx/SCLx
011200 38/88
ACKSx BIT
TSTAx BIT
XMIT BUF
STOx BIT
CONDITION
STAx BIT
X/Rx BIT
TXIx BIT
START
WRITE
Master Transmit
ACTION TAKEN BY FIRMWARE
ALTERNATIVE CONDITION
Ç Ç Ç Ç É É É É
MSB
1
É É É É Ç Ç Ç Ç
S
SLAVE ADDRESS
SLAVE ADDR.
2
XMIT: UNTIL SHIFT REG. LOAD
RECEIVE: REC. BUF. FULL
3, 6
CLOCK LINE HELD LOW
R/W
0
Ç Ç Ç Ç
7
Ç Ç Ç
A
Ç Ç Ç
Ç Ç
Ç
DIR. BIT
DATA
8
R/W
MASTER TO SLAVE XFER
SLAVE TO MASTER XFER
RECEIVER
Ç Ç Ç Ç
FROM
ACK
ACK
A
9
Ç Ç Ç Ç
DATA
Ç Ç Ç Ç
mitted, the TSTAx flag will be set. In addition, the X/Rx
bit will be set to a 1, indicating transmit operation is in
effect.
In response to TSTAx being set, the firmware can now
write to the transmit buffer an initial byte for the message
as follows:
A/A
7
Ç Ç Ç Ç
1
É É É É
Sr
É É É É
6
MULTI–BYTE XFERS
REPEATED FOR
7–bit Slave Address
SLAVE ADDR.
2
5
A = ACKNOWLEDGE (SDAx LOW)
S = START CONDITION
Sr = REPEAT START CONDITION
P = STOP CONDITION
A = NEGATIVE ACKNOWLEDGE (SDAx HIGH)
3, 8
RECEIVER
Ç Ç Ç Ç
4
RECEIVER
0
FROM
R/W
FROM
Ç Ç Ç Ç
NAK
ACK
ACK
3
9
Ç Ç Ç
Ç Ç Ç
A
2
DATA
Ç Ç Ç Ç
CONDITION
REPEAT START
1
A/A
CONDITION
STOP OR
Ç Ç Ç Ç
P
STOP
REPEAT
START
0
0