Production Data
WM8321
22 SYSTEM STATUS LED DRIVERS
22.1 GENERAL DESCRIPTION
The WM8321 provides two System Status LED Drivers. These are digital outputs intended for driving
LEDs directly. The LED outputs can be assigned to indicate OTP Program status or Power State
status. They can also be commanded directly via register control, in order to provide any other
required functionality.
22.2 LED DRIVER CONTROL
LED Drivers are configurable in the ON and SLEEP power states only. The functionality of the LED
Drivers is controlled by the LEDn_SRC register bits, as described in Table 59.
ADDRESS
R16460
(404Ch)
BIT
LABEL
DEFAULT
DESCRIPTION
LED1 Source
LED1_SRC
[1:0]
15:14
11
(Selects the LED1 function.)
00 = Off
Status LED1
01 = Power State Status
10 = Reserved
11 = Manual Mode
Note - LED1 also indicates
completion of OTP Auto Program
R16461
(404Dh)
LED2_SRC
[1:0]
LED2 Source
15:14
11
(Selects the LED2 function.)
00 = Off
Status LED2
01 = Power State Status
10 = Reserved
11 = Manual Mode
Note - LED2 also indicates an OTP
Auto Progam Error condition
Table 59 System Status LED Control
22.2.1 OTP PROGAM STATUS
The LED drivers indicate the status of the OTP Auto Program function, where the contents of the
external InstantConfig™ EEPROM (ICE) memory are automatically programmed into the OTP. See
Section 14.6.3 for further details of the OTP Auto Program function.
When the OTP Auto Program function is executed, the System Status LED drivers follow the
functionality defined in Table 60.
LED DRIVER
LED1
DESCRIPTION
DRIVE MODE
Constant
LED ‘ON’
TIME
ON:OFF
DUTY CYCLE
OTP Auto Program
Complete
n/a
n/a
LED2
OTP Auto Progam Error
Constant
n/a
n/a
Table 60 System Status LED Outputs - OTP Program Status
The OTP Program Status LED outputs will continue until a Device Reset.
Note that the OTP Program Status is always indicated via the LED outputs, regardless of the
LEDn_SRC register fields.
PD, February 2012, Rev 4.0
115
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
