P1801 Proposal Discussion

April 21, 2023 -- 2

Wireless network access at Magma

• SSID (not broadcast): lava64 bit key or 10 digit Hex key : 00000fffff

April 21, 2023 -- 3

Get commands for P1801

• Why are these needed?• To allow for instrumentality without the requirement to

delete everything and re-source the entire UPF file.• For ECO’s or modifications later on in the flow, mistakes

happen and having the ability to change modify (via get / delete commands) becomes advantageous.

• To aid convergence with other ‘low power’ formats• It is part of out ‘extent’ document to aid in convergence so

by providing get* and ‘atomic’ operations to access logical information will greatly aid in this convergence.

• After the acceptance of ‘proposal 6’ for XYZ access to logical information would also be beneficial.

April 21, 2023 -- 4

Get commands for P1801

• There are two proposals for the implementation of a get command. • Before we cover the two proposals, it should be made clear that the

proposals have further been subdivided• Get commands for UPF objects

• The definition of a UPF object is• A retention strategy, isolation strategy, isolation strategy, power domain, domain

colorization of a net etc..

• Atomic get commands for logical ‘database’ access / queries• Thus providing access to logical information, such as nets, pins, design elements

etc.

• The get command should be able to• Return information formatted as a tcl list• Be able to be write the information to a file• Be flexible so that we can

• List defined UPF objects• Easily query the entire contents of a UPF object• Have the ability to query individual options.

April 21, 2023 -- 5

Proposal 1

• Have a generic get command i.e. get_upf_object that could be used to query UPF objects.• This got shot down very quickly internally. The main

negatives were• This command will be too complex to handle all the options of the

various strategies.

• It ‘feels’ more intuitive to have a get command for a corresponding set command.

• The command would for ever be changing whenever a new set command was added.

April 21, 2023 -- 6

Proposal 2

• Have a corresponding get_* command for each set_* command where appropriate.• See overleaf for a matrix of commands that are appropriate for s

get/delete command

• The benefits of this approach• It’s clear what the command is going to do

• The options can be easily tailored to the type of data that is being retrieved

• As new commands are added it is easy to add the corresponding get command where appropriate

• The down sides• Sorry Joe!

• A lot more commands.

April 21, 2023 -- 7

Proposal 2

• NB, all get commands will return a tcl list, I’ve used a newline just for ease of reading.

• The current scope will be used as the anchor point for the ‘query’

• Using the interleaver example

upf_cmd> set_scope /upf_cmd> get_power_domainPD_interleaverPD_rx PD_tx

upf_cmd> get_power_domain –hierPD_interleaverPD_rx PD_txin2wire/PD_rdyacptout2wire/PD_rdyacpt

April 21, 2023 -- 8

Proposal 2

• Move information can be obtained by specifying the domain• If no options are specified the entire string required to recreate the domain is returned.• A –file option could also be easily added to write this information to a file if desired.

upf_cmd> get_power_domain PD_rxcreate_power_domain PD_rx -elements {in2wire pkt_counter}

• If specific information is required then options can be specified.• ONLY one option is permitted at a time.• -hier NOT permitted.

upf_cmd> get_power_domain PD_tx -elementsfifoout2wire

• How to handle –include_scope?upf_cmd> get_power_domain PD_Interleaver –elements.

April 21, 2023 -- 9

1877 / 1889 - Precedence And Regular Expressions

• Recap• These mantis issues talk about precedence rules, regular expression

support and the ability to specify an exclude list.

• I agree a form of wildcarding is required to provide a practical method of specifying a group of elements.

• There have been discussions on whether the wildcards should be string expansions or regular expressions.• Why not provide both?

April 21, 2023 -- 10

1877 / 1889 - Precedence And Regular Expressions

• Use simple string matching for the all commands, and where more powerful regexp is required the upf_find command can be used i.e.

• For example if O is an 8 bit output bus [0:7]•-elements {a/b/O[*]}

• This would select all eight bits•-elements {[upf_find a/b O[0-5] –type port –regexp]}

• This would select 6 bits (0- 6)

• NB each tool provider should verify what is acceptable where [] are concerned, so that consistent examples can be provided.• For example Magma’s TCL parser would recognize the above as a bus

expansion, and would not try to execute a command called *. It might need to be re-written as:• -elements {a/b/O\[*\]}

April 21, 2023 -- 11

1877 / 1889 - Precedence And Regular Expressions

• It as been raised a number of times that there is a desire for the specification of an exclusion list.

• As long as this is clearly specified this would also prove a powerful filtering mechanism.

• If we take the previous example of the 8 bit output bus, and we want to insert a levelshifter on all output bits except bit 7, we could:

• set_level_shifter myshift –domain PD0 –elements {O[*]} –exclude {O[7]}

• Alternatively

• set_level_shifter myshift –domain PD0 –elements {O[*]}• set_level_shifter myshift –domain PD0 –exclude {O[7]}

• The exclude effectively acts like a clear • If an object is specified in an exclude list then there is no way in THAT strategy

of specifying any other behavior than the ‘default’

April 21, 2023 -- 12

1877 / 1889 - Precedence And Regular Expressions

• The following would NOT be allowed

• set_level_shifter myshift –domain PD0 –elements {O[*]} –location self

• set_level_shifter myshift –domain PD0 –exclude {O[7]}• set_level_shifter myshift –domain PD0 –elements {O[7]} –location parent

• The following would be allowed• set_level_shifter myshift1 –domain PD0 –elements {O[*]} –location self

• set_level_shifter myshift1 –domain PD0 –exclude {O[7]}• set_level_shifter myshift2 –domain PD0 –elements {O[7]} –location parent

• While I am on the set_level_shifter command

• Does anyone have any objection in changing –applies_to to –default <output, input, both, none> both

• I.e. if you have not explicity specified a –no_shift for an element then the default applies, this just seems clearer than the current definition.

April 21, 2023 -- 13

1877 / 1889 - Precedence And Regular Expressions Name Qualification

• A lot of commands have the potential for ambiguity i.e. the –elements option on set_retention_control.• How do we distinguish a named process versus, a cell versus a net?• What is the precedence order?

• There have been proposals to expand the number of additional options to each commands, so each ‘object’ type is specified separately, but there were also complaints against this to.

• Name qualification is a powerful unambiguous method by which we can simply the number of options and allow for combined lists of different objects.

• Name qualification could be of the form• scope/[qualifier]:object• For example, all of the following are valid and unambiguous

• /in2wire/domain:pdyacpt• /in2wire/net:pdyacpt• /in2wire/cell:pdyacpt• /in2wire/process:pdyacpt• /in2wire/pst:pdyacpt

April 21, 2023 -- 14

1877 / 1889 - Precedence And Regular Expressions Name Qualification

• Name qualification could be used for all objects.

• If an object is not specified with a name qualification then the specified precedence rules would apply.• Pin

• Net

• Design element

• Process

• Strategy

April 21, 2023 -- 15

upf_find

• EDA tools of course provide the ability to search the logical and physical design.

• UPF to some extent also needs this capability to provide portability between tools.

• The upf_find command could be used to replace the –all_inputs / all_outputs options of levelshifter and isolation cell commands.

upf_find <domain | scope> search_string-type <net|port|pin|design_element>-direction <in|out>-hier

• Examples of use• upf_find PD_rx * –type pin –direction in

• Will return all the input pins on the PD_rx domain boundary

• upf_find /fifo * -type design_element • Would return all the design elements in /fifo

• upf_find /fifo PMY_.* -type design_element -regxp• Would return all the design elements in /fifo that start with PMY_

April 21, 2023 -- 16

upf_find

• Assume the logical and physical hierarchy is identical in the example below.

• Domain boundary• The inputs of the Orange domain are any signal that goes

from• A->B

• C->B

A

B

D C

April 21, 2023 -- 17

UPF Delete

• To help facilitate incrementally and the ‘interactive’ use of UPF the ability to delete the following UPF objects would be desirable• Domains• Strategies • Net colorization• PST’s• Power switches

• This could also be achieved through two approaches• Individual commands • delete_domain, delete_retention_strategy etc..

• A single ‘powerful’ delete command• delete_upf_object <object>

• upf_command> delete_upf_object PD_rf• This appraoch would require name qualification to be accepted by the

comittee.

April 21, 2023 -- 18

UPF Delete

• The upf delete command could also be one possible solution to Steve’s domain_merge problem on the interlever.

April 21, 2023 -- 19

Levelshifter / Iso Enhancements

• LS/ISO commands are currently pin based.

• A path based approach would provide added flexibility.

PD1 PD3PD2

PD1 PD3PD2

ls –from PD1ls –from PD1 –to PD3

April 21, 2023 -- 20

Levelshifter / Iso Enhancements

• However the current specification we have in P1801 would still allow correct specification, it just takes more lines.• Additional of physical information makes this even more

complicated.

• Maybe this is best left in the implementation tool domain as value add?

April 21, 2023 -- 21

Levelshifter / Iso Enhancements

• We do lack clear semantics on the supporting combined levelshifter and isolation cells (so called combo cells)

• One possible solution would to allow specification through the map commands.• If an output of a domain had both an lS and ISO strategy and the map

command for both specified a combo cell.

• Another would be to provide a combined LS and ISO command, with the appropriate set/map commands.

• Another would be to add a –combined option to the set LS/ISO commands, that if specified for either command would instruct the implementation tool to use a combined cell.

• In some cases this will not be possible (i.e. different locations specified) so could be seen as an optimization constraint…

April 21, 2023 -- 22

Switch Cells

• Switch cells are currently created in the scope.

• In the physical world this will not always be guaranteed, and will quite like be a rare occurrence.• The scope was chosen so that there was an unambiguous

location.

• We need to look at a mechanism to also allow the user to specify the desired logical location.

• Also need to decide on how we want to represent the logical connectivity between disjoint switched voltage islands of the same domain.

April 21, 2023 -- 23

Switch Cell scope/extent

PD_Interleaver

PD_rx

in2wire pktcntr

PD_tx

out2wire

fifo

ram

vdd_pad

vss_pad

rx_iso_en

tx_iso_en

rx_sleep

tx_sleep

LOGICAL

PD_Interleaver

in2wire pktcntr

out2wire

fifo

ram

vdd_pad

vss_pad

rx_iso_en

tx_iso_en

rx_sleep

tx_sleep

PHYSICAL

rx_iso_en

tx_iso_en