pcf8814 NXP Semiconductors, pcf8814 Datasheet - Page 56

• Manufacturer Part Number: pcf8814
• Description: Pcf8814 65 X 96 Pixels Matrix Lcd Driver
• Manufacturer: NXP Semiconductors

Philips Semiconductors
17.5
Table 32 OTP instructions
17.5.1
This instruction puts the device into the calibration mode.
This mode enables the shift register for loading and allows
programming of the non-volatile OTP cells to take place. If
the seal bit is set, then this mode can not be accessed and
the instruction will be ignored. Once in calibration mode,
data may be loaded into the shift register via the ID1 and
ID2 instructions (on the falling edge of SCLK).
The CALMM mode may be left by setting the CALMM bit
to logic 0. Reset will also clear this mode.
The programming can only take place when OTP Switch
Enable (OSE) has been set to logic 1. This enables the
V
common for V
module, it is necessary to disconnect V
OTP cells during normal operation. Reset will also clear
this mode
17.5.2
The action of the Refresh instruction is to force the OTP
shift register to re-load from the non-volatile OTP cells.
This instruction takes up to 5 ms to complete. During this
time all other instructions may be sent.
2003 Mar 13
OTP programming
DON (refresh)
Load 0
Load 1
OTPPROG
65
NAME
Interface commands
CALMM
R
96 pixels matrix LCD driver
input to be passed to the OTP cells. Since it is
EFRESH
OTPPROG
D/C
0
0
0
0
to be tied to SCLH/SCE on the
D7
1
1
1
1
D6
1
0
1
1
OTPPROG
D5
1
1
0
0
COMMAND BYTE
D4
1
0
1
1
from the
D3
0
1
1
1
56
D2
0
1
0
0
In the PCF8814 the Refresh instruction is associated with
the DON instruction such that the shift register is
automatically refreshed every time DON is enabled or
disabled. Note however, that if this instruction is sent while
in power-down mode, the DON bit will be updated but the
refreshing is delayed until the device leaves power-down.
17.6
In Table 33 an example sequence of commands and data
is shown. In this example the shift register is filled with the
following data: MMVPR = 1101 0000, and the seal bit is
logic 0.
It is assumed that the PCF8814 has just been reset. After
transmitting the last bit the PCF8814 can exit or remain in
CALMM mode (see step 1).
After this sequence has been applied it is possible to
observe the impact of the data shifted in. The described
sequence is however not useful for OTP programming
because the number of bits with the value “1” is greater
than that allowed for programming (see Section 17.7).
Fig.53 shows the shift register after this action.
OSE CALMM enter calibration mode and control
D1
1
0
0
Example of filling the shift register
DON
D0
0
1
programming
display ON/OFF
write 0 to shift register
write 1 to shift register
ACTION
Objective specification
PCF8814