ST7LITEU09 STMicroelectronics, ST7LITEU09 Datasheet - Page 29

• Manufacturer Part Number: ST7LITEU09
• Description: ST7ULTRALITE - 8-BIT MCU WITH 2K SINGLE VOLTAGE FLASH MEMORY, ADC, TIMERS
• Manufacturer: STMicroelectronics

Specifications of ST7LITEU09

• 2k Bytes Single Voltage Flash Program Memory With Read-out Protection, In-circuit And In-application Programming (icp And Iap). 10k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55°C
• 128 Bytes Data Eeprom. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55°C
• Clock Sources: internal trimmable 8MHz RC oscillator, internal low power, low frequency RC oscillator or external clock
• Five Power Saving Modes: Halt, Auto Wake Up from Halt, Active-Halt, Wait and Slow
• One 8-bit Lite Timer (lt) With Prescaler Including: watchdog, 1 realtime base and 1 input capture

ST7LITEU05 ST7LITEU09
6.3.4
Figure 11. CPU registers
1.
Condition code register (CC)
The 8-bit condition code register contains the interrupt mask and four flags representative of
the result of the instruction just executed. This register can also be handled by the PUSH
and POP instructions.
Reset value: 111x 1xxx
These bits can be individually tested and/or controlled by specific instructions.
Bit 4 = H Half carry bit
Bit 3 = I Interrupt mask bit
X = undefined value
This bit is set by hardware when a carry occurs between bits 3 and 4 of the ALU during
an ADD or ADC instruction. It is reset by hardware during the same instructions.
0: No half carry has occurred.
1: A half carry has occurred.
This bit is tested using the JRH or JRNH instruction. The H bit is useful in BCD
arithmetic subroutines.
This bit is set by hardware when entering in interrupt or by software to disable all
interrupts except the TRAP software interrupt. This bit is cleared by software.
0: Interrupts are enabled.
1: Interrupts are disabled.
This bit is controlled by the RIM, SIM and IRET instructions and is tested by the JRM
and JRNM instructions.
7
1
RESET VALUE = STACK HIGHER ADDRESS
RESET VALUE = RESET VECTOR @ FFFEh-FFFFh
15
15
RESET VALUE = 1
PCH
1
8
8 7
RESET VALUE = XXh
RESET VALUE = XXh
RESET VALUE = XXh
7
7
7
7
1
7
1 1 X 1 X X
1 1 H I
1
PCL
N Z
H
Read/write
0
0
0
0
X
0
0
C
ACCUMULATOR
X INDEX REGISTER
Y INDEX REGISTER
PROGRAM COUNTER
CONDITION CODE REGISTER
STACK POINTER
I
N
Central processing unit
Z
C
0
29/139