TS87C54X2-VCB Atmel, TS87C54X2-VCB Datasheet - Page 14

• Manufacturer Part Number: TS87C54X2-VCB
• Description: IC MCU 8BIT 16K OTP 40MHZ 44PLCC
• Manufacturer: Atmel
• Series: 87Cr

Specifications of TS87C54X2-VCB

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40/30MHz
• Connectivity: UART/USART
• Peripherals: POR, WDT
• Number Of I /o: 32
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: OTP
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

8. Timer 2
8.1
14
Auto-Reload Mode
AT/TS8xC54/8X2
The timer 2 in the
It is a 16-bit timer/counter: the count is maintained by two eight-bit timer registers, TH2 and TL2,
connected in cascade. It is controlled by T2CON register (See Table 8-1) and T2MOD register
(See Table 8-2). Timer 2 operation is similar to Timer 0 and Timer 1. C/T2 selects F
operation) or external pin T2 (counter operation) as the timer clock input. Setting TR2 allows TL2
to be incremented by the selected input.
Timer 2 has 3 operating modes: capture, autoreload and Baud Rate Generator. These modes
are selected by the combination of RCLK, TCLK and CP/RL2 (T2CON), as described in the
Atmel Wireless & Microcontrollers 8-bit Microcontroller Hardware description.
Refer to the Atmel Wireless & Microcontrollers 8-bit Microcontroller Hardware description for the
description of Capture and Baud Rate Generator Modes.
In
The auto-reload mode configures timer 2 as a 16-bit timer or event counter with automatic
reload. If DCEN bit in T2MOD is cleared, timer 2 behaves as in 80C52 (refer to the Atmel Wire-
less & Microcontrollers 8-bit Microcontroller Hardware description). If DCEN bit is set, timer 2
acts as an Up/down timer/counter as shown in Figure 8-1. In this mode the T2EX pin controls
the direction of count.
When T2EX is high, timer 2 counts up. Timer overflow occurs at FFFFh which sets the TF2 flag
and generates an interrupt request. The overflow also causes the 16-bit value in RCAP2H and
RCAP2L registers to be loaded into the timer registers TH2 and TL2.
When T2EX is low, timer 2 counts down. Timer underflow occurs when the count in the timer
registers TH2 and TL2 equals the value stored in RCAP2H and RCAP2L registers. The under-
flow sets TF2 flag and reloads FFFFh into the timer registers.
The EXF2 bit toggles when timer 2 overflows or underflows according to the the direction of the
count. EXF2 does not generate any interrupt. This bit can be used to provide 17-bit resolution
• Auto-reload mode with up or down counter
• Programmable clock-output
TS80C54/58X2
TS80C54/58X2
Timer 2 includes the following enhancements:
is compatible with the timer 2 in the 80C52.
4431E–8051–04/06
OSC
/12 (timer