Z8F042AHJ020SC00TR Zilog, Z8F042AHJ020SC00TR Datasheet - Page 180

• Manufacturer Part Number: Z8F042AHJ020SC00TR
• Description: IC ENCORE XP MCU FLASH 4K 28SSOP
• Manufacturer: Zilog
• Series: Encore!® XP®r

Specifications of Z8F042AHJ020SC00TR

• Core Processor: Z8
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: IrDA, UART/USART
• Peripherals: Brown-out Detect/Reset, LED, LVD, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 23
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Z8F042AHJ020SC00T

Non-Volatile Data Storage
Operation
NVDS Code Interface
PS022825-0908
Note:
Byte Write
The Z8 Encore! XP
element of up to 128 bytes. This memory can perform over 100,000 write cycles.
The NVDS is implemented by special purpose Zilog
memory, which are not user-accessible. These special-purpose routines use the Flash
memory to store the data. The routines incorporate a dynamic addressing scheme to
maximize the write/erase endurance of the Flash.
Different members of the Z8 Encore! XP F082A Series feature multiple NVDS array sizes.
See
Also the members containing 8 KB of Flash memory do not include the NVDS feature.
Two routines are required to access the NVDS: a write routine and a read routine. Both of
these routines are accessed with a CALL instruction to a pre-defined address outside of the
user-accessible program memory. Both the NVDS address and data are single-byte values.
Because these routines disturb the working register set, user code must ensure that any
required working register values are preserved by pushing them onto the stack or by
changing the working register pointer just prior to NVDS execution.
During both read and write accesses to the NVDS, interrupt service is NOT disabled. Any
interrupts that occur during the NVDS execution must take care not to disturb the working
register and existing stack contents or else the array may become corrupted. Disabling
interrupts before executing NVDS operations is recommended.
Use of the NVDS requires 15 bytes of available stack space. Also, the contents of the
working register set are overwritten.
For correct NVDS operation, the Flash Frequency Registers must be programmed based
on the system clock frequency (see
Registers
To write a byte to the NVDS array, the user code must first push the address, then the data
byte onto the stack. The user code issues a
byte-write routine (0x10B3). At the return from the sub-routine, the write status byte
Z8 Encore! XP
on page 145
®
®
F082A Series devices contain a non-volatile data storage (NVDS)
).
F082A Series Family Part Selection Guide
Flash Operation Timing Using the Flash Frequency
CALL
instruction to the address of the
®
software stored in areas of program
Z8 Encore! XP
Product Specification
Non-Volatile Data Storage
on page 3 for details.
®
F082A Series
169