MAX16067 Datasheet, PDF (41/47 Pages) Maxim Integrated Products – 6-Channel, Flash-Configurable System Manager with Nonvolatile Fault Registers

6-Channel, Flash-Configurable System Manager
with Nonvolatile Fault Registers
SETFLSHADD: This is an extension to the standard
IEEE 1149.1 instruction set that allows access to the
flash page. Flash registers include ADC conversion
results, DACOUT enables, and GPIO input/output data.
Use this page to access registers 200h-2FFh.
RSTFLSHADD: This is an extension to the standard
IEEE 1149.1 instruction set. Use RSTFLSHADD to return
to the default page and disable access to the flash page.
SETUSRFLSH: This is an extension to the standard
IEEE 1149.1 instruction set that allows access to the user
flash page. When on the configuration flash page, send
the SETUSRFLSH command, all addresses are recog-
nized as flash addresses only. Use this page to access
registers 300h–3FFh.
RSTUSRFLSH: This is an extension to the standard
IEEE 1149.1 instruction set. Use RSTUSRFLSH to return
to the configuration flash page and disable access to
the user flash.
Restrictions When Writing to Flash
Flash must be written to 8 bytes at a time. The initial
address must be aligned to 8-byte boundaries—the
3 LSBs of the initial address must be ‘000’. Write the
8 bytes using 8 successive Write Data commands. A
write operation requires 122ms for each 8-byte block.
After programming a block, check r20h[1] (see Table
31) to make sure the write operation is complete before
attempting to write the next block.
Applications Information
Unprogrammed Device Behavior
When the flash has not been programmed using the
JTAG or SMBus interface, the default configuration of
the EN_OUT_ outputs is open drain active low. This
means that the EN_OUT_ outputs are high impedance.
When it is necessary to hold an EN_OUT_ high or low to
prevent premature startup of a power supply before the
flash is programmed, connect a resistor from EN_OUT_
to ground or the supply voltage. Avoid connecting a
resistor to ground when the output is to be configured as
open drain with a separate pullup resistor.
Device Behavior at Power-Up
When VCC is ramped from 0V, the RESET output is
high impedance until VCC reaches 1.4V, at which point
RESET goes low. All other outputs are high impedance
until VCC reaches 2.7V, then the flash contents are cop-
ied into register memory. This takes 150Fs (max) after
which the outputs assume their programmed states.
Programming the MAX16067 in Circuit
The MAX16067 can be programmed in the application
circuit by taking into account the following points during
circuit design:
U The MAX16067 needs to be powered from an inter-
mediate voltage bus or auxiliary voltage supply so
programming can occur even when the board’s power
supplies are off. This could also be achieved by using
ORing diodes so that power can be provided through
the programming connector.
U The SMBus or JTAG bus lines should not connect
through a bus multiplexer powered from a voltage rail
controlled by the MAX16067. If the device needs to be
controlled by an on-board FP, consider connecting the
FP to one bus (such as SMBus) and use the other bus
for in-circuit programming.
U An unprogrammed MAX16067’s EN_OUT_s go high
impedance. Ensure that this does not cause undesired
circuit behavior. If necessary, connect pulldown resis-
tors to prevent power supplies from turning on.
Table 31. RESET State, Flash State, and Reset Reason
REGISTER ADDRESS
r20h
BIT RANGE
[0]
[1]
[2]
[3]
[7:4]
DESCRIPTION
Reset Output State
0 = RESET is low
1 = RESET is high
1 = Flash memory is busy
1 = Last reset asserted due to EN going low
1 = Last reset asserted due to watchdog timeout
Not used
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