AT83EC5123 ATMEL Corporation, AT83EC5123 Datasheet - Page 111

• Manufacturer Part Number: AT83EC5123
• Description: (AT8xx512x) Smart Card Reader ICs
• Manufacturer: ATMEL Corporation

Figure 73. Timer/Counter x (x = 0 or 1) in Mode 1
Figure 74. Mode 1 Overflow Period Formula
Mode 2 (8-bit Timer with Auto-
Reload)
Figure 75. Timer/Counter x (x = 0 or 1) in Mode 2
Figure 76. Mode 2 Autoreload Period Formula
4202B–SCR–07/03
INTx#
FCK_Tx
INTx#
FCK_Tx
Tx
Tx
TMOD reg
TMOD reg
GATEx
GATEx
/6
/6
TMOD reg
C/Tx#
Mode 2 configures Timer 0 as an 8-bit Timer (TL0 register) that automatically reloads
from the TH0 register (see Figure 75). 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.
Figure 76 gives the autoreload period calculation formula when in timer mode.
0
1
TCON reg
TCON reg
TRx
TRx
TMOD reg
C/Tx#
TFx
0
1
PER
TFx
=
PER
6
=
(65536 – (THx, TLx))
6 (256 – THx)
F
F
CK_Tx
CK_Tx
(8 bits)
THx
(8 bits)
(8 bits)
THx
TLx
(8 bits)
TLx
Overflow
Overflow
TCON reg
TCON reg
TFx
TFx
AT8xC5122/23
Timer x
Interrupt
Request
Timer x
Interrupt
Request
111