84PCE:Ports:0005

From WikiTI
Revision as of 23:57, 20 February 2021 by Zeroko (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Synopsis

Port Number: 0005

Function: Controls access to ports & the backlight PWM.

Details

This port enables access to various parts of the ASIC.

Bit [0]

Enables access to F000 port range.

Bit [1]

Enables access to E000 port range (ARM coprocessor).

Bit [2]

Enables access to D000 port range (LCD SPI).

Bit [3]

Latches value written, no apparent effect.

Bit [4]

Enables access to B000 port range (backlight).

Bit [5]

Enables writes to A000 port range (keypad). When disabled, read access still succeeds.

Bit [6]

Enables the backlight PWM. When disabled, the screen will be fully dark or bright, depending on which part of the PWM cycle it was in when last enabled.

Bit [7]

Writes have no apparent effect, value does not latch.