Rainbow Electronics MAX66100 - Manual (Page 10)

MAX66100
Request Flags
The command descriptions on the subsequent pages
begin with a byte called request flags. The ISO 15693
standard defines two formats for the request flags byte.
The state of the Inventory_flag bit controls the function
of the bits in the upper half of the request flags byte.
The function of the request flags byte is as follows.
Inventory_flag Bit Not Set
Bits 8, 4: No Function. These bits have no function.
They must be transmitted as 0.
Bit 7: Options Flag (Option_flag). This bit is used with
block read commands to include the block security sta-
tus in the response. If not applicable for a command,
the Option_flag bit must be 0.
Bit 6: Address Flag (Address_flag). This bit specifies
whether all slaves in the master’s field that are in the
selected or ready state process the request (bit = 0) or
only the single slave whose UID is specified in the
request (bit = 1). If the Address_flag bit is 0, the
request must not include a UID. The combination of
both the Select_flag and Address_flag bits being set
(= 1) is not valid.
Bit 5: Select Flag (Select_flag). This bit specifies
whether the request is processed only by the slave in
the selected state (bit = 1) or by any slave according to
the setting of the Address_flag bit (bit = 0).
Bit 3: Inventory Flag (Inventory_flag). This bit must
be 1 for the Inventory command only. For all other com-
mands, this bit must be 0.
Bit 2: Data Rate Flag (Data_rate_flag). This bit speci-
fies whether the response data packet is transmitted
using the low data rate (bit = 0) or the high data rate
(bit = 1).
Bit 1: Subcarrier Flag (Subcarrier_flag). This bit
specifies whether the response data packet is transmit-
ted using a single subcarrier (bit = 0) or two subcarriers
(bit = 1).
Inventory_flag Bit Set
Bits 8, 7, 4: No Function. These bits have no function.
They must be transmitted as 0.
Bit 6: Slot Counter Flag (Nb_slots_flag). This bit
specifies whether the command is processed using a
slot counter (bit = 0) or without using the slot counter
(bit = 1).
Bit 5: Application Family Identifier Flag (AFI_flag).
To detect only slaves with a certain AFI value, the
AFI_flag bit must be 1 and the desired AFI value must
be included in the request. If the least significant nibble
of the AFI in the request is 0000b, slaves process the
command only if the most significant nibble of the AFI
matches. If the AFI in the request is 00h, all slaves
process the command regardless of their AFI.
Bit 3: Inventory Flag (Inventory_flag). This bit must
be 1 for the Inventory command only. For all other com-
mands, this bit must be 0.
Bit 2: Data Rate Flag (Data_rate_flag). This bit speci-
fies whether the response data packet is transmitted
using the low data rate (bit = 0) or the high data rate
(bit = 1).
Bit 1: Subcarrier Flag (Subcarrier_flag). This bit
specifies whether the response data packet is transmit-
ted using a single subcarrier (bit = 0) or two subcarriers
(bit = 1).
ISO 15693-Compliant 64-Bit UID
10 ______________________________________________________________________________________
BIT 8 (MSb) BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 (LSb)
0 Option_flag Address_flag Select_flag 0
Inventory_flag
(= 0)
Data_rate_flag Subcarrier_flag
BIT 8 (MSb) BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 (LSb)
0 0 Nb_slots_flag AFI_flag 0
Inventory_flag
(= 1)
Data_rate_flag Subcarrier_flag
Request Flags, Inventory_flag Bit Not Set
Request Flags, Inventory_flag Bit Set