PMBus Interface Registers Reference
393
SNIU028A – February 2016 – Revised April 2016
Copyright © 2016, Texas Instruments Incorporated
PMBus Interface/I2C Interface
10.10.9 PMBus Control Register 3 (PMBCTRL3)
Address FFF7F620
Figure 10-61. PMBus Control Register 3 (PMBCTRL3)
24
23
I2C_MODE_EN*
CLK_HIS_DIS* or CLK_HI_EN*
R/W-0
R/W-1 or R/W-0
22
21
20
19
18
17
16
MASTER_EN
SLAVE_EN
CLK_LO_DIS
IBIAS_B_EN
IBIAS_A_EN
SCL_DIR
SCL_VALUE
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
15
14
13
12
11
10
9
8
SCL_MODE
SDA_DIR
SDA_VALUE
SDA_MODE
CNTL_DIR
CNTL_VALUE
CNTL_MODE
ALERT_DIR
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
ALERT_VALUE
ALERT_MODE
CNTL_INT
_EDGE
FAST_MODE_
PLUS
FAST_MODE
BUS_LO_INT_
EDGE
ALERT_EN
RESET
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 10-13. PMBus Control Register 3 (PMBCTRL3) Register Field Descriptions
Bit
Field
Type
Reset
Description
24
I2C_MODE_EN*
R/W
0
I2C Mode Enable – Utilized for Master mode only
0 = I2C Mode Disabled (Default)
1 = I2C Mode Enabled
The only effect of I2C_MODE_EN is to remove the automatic insertion of number of
bytes in block writes in master mode.
*Only available on UCD3138A64 and UCD3138128 A and non-A versions
23
CLK_HI_DIS*
R/W
1
Clock High Timeout Disable
0 = Clock High Timeout Enabled
1 = Clock High Timeout Disabled (Default)
*Only available on UCD3138A64 and UCD3138128 A and non-A versions
23
CLK_HI_EN*
R/W
0
Clock High Timeout Enable
0 = Clock High Timeout Disabled (Default)
1 = Clock High Timeout Enabled
*Only available on UCD3138A and UCD3138064A
22
MASTER_EN
R/W
0
PMBus Master Enable
0 = Disables PMBus Master capability (Default)
1 = Enables PMBus Master capability
21
SLAVE_EN
R/W
0
PMBus Slave Enable
0 = Disables PMBus Slave capability
1 = Enables PMBus Slave capability (Default)
20
CLK_LO_DIS
R/W
0
Clock Low Timeout Disable
0 = Clock Low Timeout Enabled (Default)
1 = Clock Low Timeout Disabled
19
IBIAS_B_EN
R/W
0
PMBus Current Source B Control
0 = Disables Current Source for PMBUS address detection thru ADC (Default)
1 = Enables Current Source for PMBUS address detection thru ADC
18
IBIAS_A_EN
R/W
0
PMBus Current Source A Control
0 = Disables Current Source for PMBUS address detection thru ADC (Default)
1 = Enables Current Source for PMBUS address detection thru ADC
17
SCL_DIR
R/W
0
Configures direction of PMBus clock pin in GPIO mode
0 = PMBus clock pin configured as output (Default)
1 = PMBus clock pin configured as input