MC68711E20CFNE3 Datasheet, PDF (47/242 Pages) –

EPROM/OTPROM
IRQE — Configure IRQ for Edge-Sensitive Only Operation Bit
Refer to Chapter 5 Resets and Interrupts.
DLY — Enable Oscillator Startup Delay Bit
0 = The oscillator startup delay coming out of stop mode is bypassed and the MCU resumes
processing within about four bus cycles.
1 = A delay of approximately 4000 E-clock cycles is imposed as the MCU is started up from the stop
power-saving mode. This delay allows the crystal oscillator to stabilize.
CME — Clock Monitor Enable Bit
Refer to Chapter 5 Resets and Interrupts.
Bit 2 — Not implemented
Always reads 0
CR[1:0] — COP Timer Rate Select Bits
The internal E clock is divided by 2¹⁵ before it enters the COP watchdog system. These control bits
determine a scaling factor for the watchdog timer. Refer to Chapter 5 Resets and Interrupts.
2.4 EPROM/OTPROM
Certain devices in the M68HC11 E series include on-chip EPROM/OTPROM. For instance:
• The MC68HC711E9 devices contain 12 Kbytes of on-chip EPROM (OTPROM in non-windowed
package).
• The MC68HC711E20 has 20 Kbytes of EPROM (OTPROM in non-windowed package).
• The MC68HC711E32 has 32 Kbytes of EPROM (OTPROM in non-windowed package).
Standard MC68HC71E9 and MC68HC711E20 devices are shipped with the EPROM/OTPROM contents
erased (all 1s). The programming operation programs zeros. Windowed devices must be erased using a
suitable ultraviolet light source before reprogramming. Depending on the light source, erasing can take
from 15 to 45 minutes.
Using the on-chip EPROM/OTPROM programming feature requires an external 12-volt nominal power
supply (V_PPE). Normal programming is accomplished using the EPROM/OTPROM programming register
(PPROG).
PPROG is the combined EPROM/OTPROM and EEPROM programming register on all devices with
EPROM/OTPROM except the MC68HC711E20. For the MC68HC711E20, there is a separate register for
EPROM/OTPROM programming called the EPROG register.
As described in the following subsections, these two methods of programming and verifying EPROM are
possible:
1. Programming an individual EPROM address
2. Programming the EPROM with downloaded data
M68HC11E Family Data Sheet, Rev. 5.1
Freescale Semiconductor
47