89C5121-SK1 Atmel, 89C5121-SK1 Datasheet - Page 75

• Manufacturer Part Number: 89C5121-SK1
• Description: KIT SMART CARD FOR AT89C5121
• Manufacturer: Atmel
• Type: Smart Cardr

Specifications of 89C5121-SK1

• Contents: Board
• For Use With/related Products: AT89C5121
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: T89C5121-SK1; T89C5121-SK1

Figure 29. Timer 0/Counter x (x = 0 or 1) in Mode 1
Mode 2 (8-bit Timer 0 with
Auto-Reload)
Figure 30. Timer 0/Counter x (x = 0 or 1) in Mode 2
Mode 3 (Two 8-bit Timer 0s)
4164G–SCR–07/06
INTx#
INTx#
Tx
Tx
TMOD reg
GATEx
TMOD reg
FCLK_Periph
GATEx
FCLK_Periph
TMOD reg
C/Tx#
Mode 2 configures Timer 0 as an 8-bit Timer 0 (TL0 register) that automatically reloads
from the TH0 register (see Figure 30). TL0 overflow sets the TF0 flag in the TCON reg-
ister and reloads TL0 with the contents of TH0, which is preset by the software. When
the interrupt request is serviced, the hardware clears TF0. The reload leaves TH0
unchanged. The next reload value may be changed at any time by writing it to the TH0
register.
Mode 3 configures Timer 0 so that registers TL0 and TH0 operate as 8-bit Timer 0s (see
Figure 31). This mode is provided for applications requiring an additional 8-bit Timer 0 or
Counter. TL0 uses the Timer 0 control bits C/T0# and GATE0 in the TMOD register, and
TR0 and TF0 in the TCON register in the normal manner. TH0 is locked into a Timer 0
function (counting F
trol (TR1) bits. Thus, operation of Timer 1 is restricted when Timer 0 is in mode 3.
TCON reg
0
1
TCON reg
TRx
TRx
TMOD reg
C/Tx#
0
1
UART
) and takes over use of the Timer 1 interrupt (TF1) and run con-
(8 bits)
THx
(8 bits)
(8 bits)
THx
TLx
(8 bits)
TLx
Overflow
Overflow
TCON reg
TCON reg
TFx
TFx
A/T8xC5121
Timer 0 x
Interrupt
Request
Timer 0 x
Interrupt
Request
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