PCF8531 datasheet(20/51 Pages) NXP

20 / 51 page

PCF8531

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Product data sheet

Rev. 05 — 10 August 2010

20 of 51

NXP Semiconductors

PCF8531

34 x 128 pixel matrix driver

Instructions

Only two PCF8531 registers, the instruction register and the data register can be directly

controlled by the MPU. Before internal operation, control information is stored temporarily

in these registers to allow interfacing to various types of MPUs which operate at different

speeds or to allow interfacing to peripheral control ICs. The PCF8531 operation is

controlled by the instructions given in Table 11.

Instructions are of four types:

• Those that define PCF8531 functions e.g. display configuration, etc.

• Those that set internal RAM addresses

• Those that perform data transfer to/from the internal RAM

• Others

In normal mode instructions which perform data transfer to/from the internal RAM are

used most frequently. Automatic incrementing by 1 of internal RAM addresses after each

data write reduces the MPU program load.

9.1 Reset

After reset or internal Power-On Reset (POR) (depending on the application), the LCD

driver is set to the following state:

• Power-down mode (PD = 1)

• Horizontal addressing (V = 0)

• Display blank (D = 0; E = 0), no icon mode (IM = 0)

• Address counter X[6:0] = 0; Y[2:0] = 0

• Bias system BS[2:0] = 0

• Multiplex rate M[1:0] = 0 (multiplex rate 1:17)

• Temperature control mode TC[2:0] = 0

• HV-gen control, HVE = 0 the high voltage (HV) generator is switched off, PRS = 0 and

S[1:0] = 0

• VLCD =0V

• RAM data is undefined

• Command page definition H[1:0] = 0

PCF8531 Datasheet(PDF) 20 Page - NXP Semiconductors