UPF低功耗实现系列博客——9 层次化UPF编码

2024-11-22

层次化UPF编码思路

Design Hierarchy

  • Block level:模块级别,如CPU/GPU等等
  • Top level:芯片去掉Block以外的部分,block被当作Black Box/Interface Logic Model
  • Chip level:整个芯片完全flatten的层次

Design Hierarchy
  • Block UPF:描述block低功耗信息的完整UPF
    • block使用的电源,以及电源与block的连接
    • block使用的低功耗单元rule
    • power state与chip level兼容
  • Top UPF:完整描述芯片的UPF
    • Top only objects的低功耗信息
    • top与block的PG/signal连接
    • Block domain声明,低功耗单元rule(看具体设计)
  • Chip UPF:
    • Top & Block UPF的组合
    • 移除重复的定义

Block UPF

  • 层次化UPF中的Block UPF编码
    • Power State:必须与Top UPF兼容
    • 只能包含该block内使用的supply set
    • 定义边界端口的低功耗属性

Block UPF example 1
# inside level shifter
create_supply_net VDD_Top
set_port_attributes -ports -driver_supply SS_VDD_TOP
set_level_shifter

# outside level shifter
set_port_attributes -ports -driver_supply SS_VDD_Block
# Block UPF:
# (1) Inside ISO & PSW:
create_supply_net VDD_Top

set port_attributes -ports -receiver_supply SS_VDD_TOP
create_power_switch ...
set isolation ...
# (2) Outside ISO & PSW.
set port_attributes -ports -receiver_supply SS_VDD Block
# (3) Inside PSW & Outside 1SO
create_supply_net VDD_Top
set_port_attributes -ports -receiver_supply SS_VDD Block
create_power_switch ...